When Pokemon evolve, they get stronger. 9 times out of 10, it's at least not terrible to do it when you can, because of both TM's and the fact that by the time you can evolve them, they will have learned most of their moves.
The evolution stones have that weird "limitation" sometimes because the evolution itself is "unnatural", and so the Pokemon, Iunno just can't learn anything else on its own.
You aren't expected to learn all of this. You aren't expected to figure everything out, and know how everything works. You're expected to experiment and try things and discover as you go. And then, once you have a really good idea of how it all works, -then- you start planning and researching and figuring everything out.
EDIT: My advice is to, instead of ever looking up anything ever at all, just play it. Don't overwhelm yourself, don't look up movesets, don't do any of that. Just get from point A, to point B. Maybe an occassional "how does X evolve into Y" here and there, but the game will take care of itself for you, if that makes any sense. Don't sweat over "Should I evolve Pikachu or keep him as is?", because I guarantee you that even if you do evolve him, you'll still be able to use moves as you go. Thunderbolt and Thunder are both TMs IIRC, and those are really the only two you should care about.
Just -play- the game, don't try and research it and catch up. You'll overwhelm yourself, I guarantee it.
I'll start working on the Eevee when I get home tonight. It's 7am here now so that's like 12 hours away. Once I start it *hopefully* won't take longer than a few hours.
