Wartortle evolves at the same level in every Pokemon game. Wartortle evolves at level 36. Wartortle will then evolve into a Blastoise.
You can't catch Wartortle in heartgold. After you beat Red on Mt. Silver you can go to Prof. Oak (he'll be in his lab in pallet) and he'll give you a Kanto starter. In your case, you can choose Squirtle and evolve it to Wartortle
Wooper will evolve at Level 20.
level 31
Level 55.
On level 40
Farfetch'd is a Pokemon that does not evolve.
Level 55
35
level 55
at level 38
at level 32