thanks for the response, that's good to hear. I don't know if these count as a simple questions but I figured I'd ask them anyways(they're about the reuni team):
-how do you deal with crawdaunt, hoopa-u, specs lele, charizard-x, weather teams and tapu fini when it has taunt? i feel like they just wreck me
-is that reuni speed just to creep past gastrodon?
-what does exactly 80 speed do for skarm?
-who eats knock offs when toxapex needs that shed shell?
-what is the best way to deal with serperior? i typically use chansey but at +6 its can fall to 2 leaf storms if i get paraed, and i hate it when lati gets paralyzed, also sometimes it has leech seed or taunt
idk what i'm doing so sorry if these questions are rly dumb
I assume u talk about this team?
https://pokepast.es/042d410ca9589552
Most pokemon you mentionned naturally have a strong matchup against this team, but you have some ways to play around them - even though they still are rough to face for this team. I personally think Gliscor should be Knock Off, so i will assume this is the move it is running in this team.
One solution is usually trying winning first with MLatias or Reuniclus - especially MLatias - which can finish weakened teams, so keep in mind this is an important out in case of bad MU - especially since they sometimes will have to take heavy damages with their wallbreaker to check your wincondition, which can be a winning trade for you. Playing aggressively and try to predict when the opponent is going to send their breaker to cripple them with a certain move or just KO them is also a way if the matchup is really deseperate (like clicking focus blast on reuniclus when you think your opponent will expect a Recover and try to send crawdaunt). You also have to pay attention to the hazard game of course, as it can either reduce your possibilities of counterplay against the opposing team or improve it if you can push stuff in the range of your win conditions.
There might be some oversights on my part in this post as well - so if anyone has something to add feel free.
-Crawdaunt

If its band: you can scout the move it locks into with Toxapex. If it locks into Crabhammer Toxapex can stay against it, otherwise you can go gliscor, which takes heavy damages but outspeed and can roost faster against it, and takes only 50-60 once it lost its Toxic Orb (Make sure to find an opportunity to trigger the Toxic Orb beforehand though!). Once this is done, you might be stuck in a weird situation where you spam roost and the opponent spams knock off, which is annoying even though roost + poison heal outdamages Knock Off slightly. If you think they will continue to spam Knock, at some point you can Knock their choice band, which will leave it unable to break Pex. Gliscor will be severely weakened after this interaction, as well as pex to a lesser extent, which can be taken advantage of by other teammates like Heatran.
If its SD: Good luck lol. Skarmory can revenge kill Crawdaunt thanks to sturdy + Body Press. You can also lure it with Reuniclus since LO Knock Off do not kill it, if they try to force Reuniclus out with crawdaunt:
252+ Atk Life Orb Adaptability Crawdaunt Knock Off vs. 252 HP / 180+ Def Reuniclus: 354-421 (83.4 - 99.2%) -- guaranteed 2HKO.
Trying to chip them as much as possible is also a plan, especially since they are limited by LO.
-Hoopa U

In general, good luck. Even winning with MLatias is hard because Hoopa-U can check MLatias pretty well if its band - though after a CM boost, MLatias is obscenely fat so NP and Specs variant might have an hard time against it.
Your counterplay against band is probably trying to catch it on a double switch or something. Trying to PP Stall Hyperspace Fury by spamming recovery moves could work. Maybe. Fortunately this mon (and crawdaunt) are very uncommon, and their niche pretty much is destroying fat lol. Just so you know, band hoopa/daunt is fully checked by pex or mola + dark resist, as you can scout what it locks into.
-Specs lele

Some mons in this team can stay against it and click their recovery move to scout what it locks into: Chansey in particular do not take more than 60 from anything Lele throws at it including Psyshock, so it can safely scout it. Reuniclus, Gliscor (if not Psychic) and Skarmory can all take a hit from full and scout the move, though this should be avoided if you need them to be healthy to check something else. When this is not possible, you will have to try to dance around its coverage - which is risky but honestly you don't have much other options once it hits the field. +1 Mega Latias can be annoying to Lele since after a mystical fire, Moonblast only does around 50%.
Try to limit its opportunity to enter the field safely as much as possible. Try to analyze the team preview before the start of the game to figure out in what scenarios Tapu Lele can enter the game: is there pivots that can bait Toxapex in and pivot against it to bring Tapu Lele? In what scenarios Tapu Lele could try to double switch into something it threatens? Those questions aren't always obvious for the untrained eye but this is part but already thinking about it help you getting better at the game.
Stacking hazards to limit Lele's opportunities as much as possible is sometimes an option too!
-Zardx

Rough MU too. Trying to get up rocks is a good idea, although ZardX can try to setup vs chansey. A way to deal with it is toxicing it with Pex - as it eats +1 Earthquake - and try to dance around it. If you don't need Chansey you can try to bait flare blitz with Skarm and sack Chansey on it, to force huge recoil on it.
-Weather teams:
MLatias is very important, as it is both a scary win condition against those teams and a very useful mon defensively, as it checks Manaphy or Venusaur. Against Rain the biggest threat is probably M-Swampert, as you don't have a clear cut answer to it. You will have to try to not let it get free entry, and once it hits the field you gotta dance around it a bit with Pex, Skarmory and maybe Mega-Latias. If it's Weavile rain you will have to outplay your opponent a lot as you need mlatias to check mana but also can be trapped by Weavile. Otherwise, once ferro and mpert are in range of MLatias you have good odds to win. Against sun try to set rocks as soon as possible as this playstyle is very vulnerable to chip in general. Try to keep MLatias for Venusaur, as it is sometimes paired with other breakers that attempt to lure MLatias such as sun boosted Firium Z Blaziken. I don't think sand teams are a very huge issue (though honestly i'm not very sure what they look like nowadays lol - same with hail - or if it is even seen as a distinct archetype)
-Taunt Tapu Fini

Glisc outspeeds it and knock it, from there it will be much easier to deal with in the long run - once PHeal is activated it kinda can switch into it. Try to force chip onto it, with hazards or moves like seismic toss or EQ. You can get some chip on it by going pex once lefties are knocked off, scald a few times and then regen off the damages taken.
-It outspeeds Pex that try to creep reuniclus i imagine? I honestly don't know
-Skarm with speed outspeeds MMawile, so you can ID faster than it, or just roost against TPunch/Fire Fang sets to win through helmet damages.
-Sometimes Pex is the only thing that can afford to switch into the knock user (like against Weavile), even if you need the shed shell. It's rough, it's sad, it's unfair and we want to cry but it's usually not the end of the world and you usually still have ways to play around matchups once this is lost.
-Serp is nasty against that kind of builds yeah. Aside from trying to prevent it to get in for free i don't think there is much you can do aside from accepting taking the para on Latias :[
Oh of course if it's taunt Serperior this team explodes and the forfeit button is our only remaining friend in this rough battle.
If you have any other questions feel free to ask, i hope this was insightful