Just let me check their Gen 1 movepools and stats and... oh, those stats suck. For your sake, I hope you're the kind of guy that fights every trainer. You might need your Pikachu to be Level 92.
For Pikachu, I don't think I need to say this with his defenses, but all out offense. Thundershock is obvious until Level 26, which is when you get Thunerbolt. Use whatever's the most powerful Normal Type Move you have at the time and Quick Attack until you get Swift, which you should keep unlit you get Double Edge unless you don't like that move. For your last move, get to The Celadon City Store as soon as you can for Submission. The few other options include Seismic Toss and nothing else even remotely close to good.
For Jigglypuff, there are many options, so I'll tell you your options, but not tell you what moveset to use. There are no boosting moves and no good defensive ones outside of Defense Curl, so I recommend offense again. For your Normal Type Move, You can get Body Slam from the S.S. Anne. Jigglypuff has very high HP, so feel free to consider Double Edge at Level 39. Sing is inaccurate, but you might want to use it. You can get Water Gun in Mt. Moon then replace it with Bubble Beam after you beat Misty. Thunderbolt is another early move which you get from Lt. Surge. When you get to the Celadon City Store, you can get Submission again, which uses Jigglypuff's higher Attack stat, if you want it up and Ice Beam from the girl on the roof and then you can go to Saffron City immediately after for Psychic. If you want to be defensive, you can also buy Double Team from the store, but I'll hate you for using that BS. When you get to Cinnabar Island, you can get the 90 Accuracy Blizzard from the Manson and Fire Blast from Blane. So yeah, lots of options. Just use what you think you need.