I got a Charizard. It evolved pretty fast.
Can we rename pokemon after we get them?
I want to change his name from Godzilla to "Go Godzilla"
So that way the game will say "Go! Go Godzilla!"
Yes. Once you get to Lavender Town you can talk to the Name Rater in one of the houses, and rename your pokemon at any time.
As for your team, you basically want a 6 different types of pokemon, so that you can handle any other pokemon that comes your way. Since you're playing Yellow Version, the game kind of spoon feeds you a pretty good team anyway. Pikachu, Charmander, Squirtle, Bulbasaur etc. But any team that has 6 different types will do you well.
Pikachu isn't amazingly strong in the games, his main strengths are his high speed and fantastic moveset. That Pikachu you have will eventually learn Thunderbolt, Thunder, Double Team, Light Screen, and Agility(of course he can only use 4 of these). So he lends himself well to your team, being a fairly heavy hitter while offering some support, particularly against Water and Flying Types.
The kind of teams I usually build are pretty random. I just kind of look into the pokedex guide on Serebii.net, and pick which ones look the coolest to me at the time, go get them in game, and then train them lol
I generally always have a Fighting type, a Ghost type, a Fire type, a Flying type, an Ice type, and a Ground type. Though honestly I am given to being lazy and lugging around my Water type HM slave and my land type HM slave, because traveling around requires them, and I can't always *** myself with getting two good pokemons out of the box, when one overleveled Pokemon can obliterate the NPC competition(especially since you can just spam potions etc.).