New to this - help rate my team!

[IrishRidire]

So I'm really not good with this at all, just starting competitive battling! I'm trying to put together a team and any help would be appreciated! All advice/criticisms welcome!
Changes in Blue

Pikachu@Leftovers
Ability: Lightning Rod
EVs: Sp att(252)and Speed(252)
Nature: Timid
-Signal Beam
-Thunderbolt
-Thunder Wave
-Grass Knot

What can I say, Pikachu is my favorite Pokemon. I figure she'll be my primary force against water and flying pokemon. I definitely love my Pikachu and wouldn't change it for anything!

Golem@Light Orb
Ability: Sturdy
Ev in ATK(252) and Hit points(252)
Nature: Adamant
-Earthquake
-Hammer Arm
-Stone Edge
-Explosion

Hopefully my Golem will be my main defense and also just to bust out some strong moves. This will be my main defense against electric types, as well as fire types. I'm choosing strong moves to just take out HP in big chunks.

Gengar@Leftovers
Ability: Levitate
EV: Sp. att(252) and Speed(252)
Nature: Modest
-Shadow Ball
-Sludge Bomb
-Focus Blast
-Energy Ball
Gengar is another all time favorite. Sucker Punch is EXTREMELY useful to me. The ghost type will make it harder to hit, and it has a nice variety of moves to take on multiple challenges. I'd like to add Sucker Punch in here somewhere but I'm not sure where.

Typhlosion@Leftovers
Ability: Flash Fire
EV in sp att(252) and Speed(252)
Nature: Timid
-Lava Plume
-Focus Blast
-Double Kick
-Will - o - whisp

I need a fire pokemon to take care of grass/steel types, so I figured Typhlosion would do the job well. I'm not positive if this is the best choice for my fire pokemon, so advice here would be especially appreciated.

Sharpedo@Choice Band
Ability: Rough Skin
Evs: 252Attack/252 Speed
Nature: Jolly
-Earthquake
-Crunch
-Aqua Jet
-Ice Fang
I need a water pokemon to take down fire pokes, and dark is useful often. The water will also be useful against rock, ground, and ghost types. Also not positive if this is the best water choice!

Skarmory (not certain if this one is a good idea?)@Leftovers
Ability: Keen Eye
Evs:Attack (100) Defense (156) and HP(252)
Nature: Impish
-Brave Bird
-Stealth Rock
-Roost
-Toxic

Flying to take care of bugs, and steel is very strong. Another choice I'm not sure about, but I decided I needed a steel pokemon in my team somewhere. Brave bird and fly will be good against all bug types.

Some things I've been considering - Not sure if Typhlosion is the best fire type choice. I've also started to like Umbreon, but I'm not sure where it could fit in!
As you can see, I love older pokemon - I plan on getting them from HG
Again, I'm brand new to this so I doubt this will be too great! Thank you in advance!

PS Also, what tiers could I compete in with this team?

 

[adventure time]

Your team is all UU and NU, with the exception of your Skarmory and Gengar, I think. Pikachu however, wouldnt hold itself up against pokemon that would stall and demolish it, such as Heatran and Salamence, who resist all of his attacks, so I think you should go for more coverage, but what would help your team most would be switching Pikachu for another pokemon, and there are certainly alot more pokemon to use than that. Electivire and Jolteon especially.

 

[IrishRidire]

Your team is all UU and NU, with the exception of your Skarmory and Gengar, I think. Pikachu however, wouldnt hold itself up against pokemon that would stall and demolish it, such as Heatran and Salamence, who resist all of his attacks, so I think you should go for more coverage, but what would help your team most would be switching Pikachu for another pokemon, and there are certainly alot more pokemon to use than that. Electivire and Jolteon especially.

Even if I got a Pikachu with REALLY good stats, it still would be useless?

 

[JH.Atlas]

Typhlosion@Leftovers
Ability: Flash Fire
EV in sp att(252) and Speed(252)
Nature: Timid
-Lava Plume
-Focus Blast
-Double Kick
-Will - o - whisp

I need a fire pokemon to take care of grass/steel types, so I figured Typhlosion would do the job well. I'm not positive if this is the best choice for my fire pokemon, so advice here would be especially appreciated.

In the UU/NU environment, Typhlosion is a good choice to deal with grass and steel types, with its nice sp.att and speed.
But why go for Double Kick? Since you run a special set, it seems rather misplaced. I recommend you replace it with HP grass (to deal with water and ground types) or HP electric (again to deal with water types, especially gyarados).
You can also consider switching Lava Plume for Flamethrower, if you want more power. But Lava Plume can be effective, if you want chances to get a burnhax to go up (but since you run will-o-wisp, that's not really necessary).
As for the items; Typhlosion makes a great recepient for choice scarf or choice specs, which would make it a great threat to the opposing team. This is just a suggestion.