I was wondering, what level does it take for a Pokemon to evolve?

Also, what are the hazards if I do not let my Pokemon evolve? Are there any disadvantages? how about advantages?

Thanks in advance.

Different pkmn evolve on different levels. The advantage of not letting a pkmn evolve is that it learns all the same moves as its evolved form but a bit earlier and sometimes unevolved forms learn moves that are unaccessible to their evolved forms, for example shroomish learns spore on lvl 54. No disadvantages really. It's just that unevolved forms are weaker...

Thanks agan.

Last question, when does a Kakuna evolve? Mine is on level 11 now and it's still a Kakuna.

For future reference, Pokemon is like Reindeer or Sheep, the singular is the same as the plural. I have a pokemon, I have 3 pokemon.

Kakuna evolves into Beedrill at level 10. If you daycared it, or pressed B during eveolution it woudn't have evolved. Level it up again, make sure it isnt holding a everstone and don't press b! And you should have a Beedrill.

I have day-cared it, so that must be it.

Thank you very much.