pidgey evolves into pidgeotto at level 18, then into pidgeot at level 36.
It evolves at level 36.
Stantler does not evolve.
graveler doesnt evolve at a level, you evolve it by trading.
Level 20.
Level 20
Level 23. 
it will evolve at lv. 20.
Your Aron will evolve at level 32 into Lairon.
14
35
Level 27.
Level 20.