What is needed to evolve Pokemon? (In the tcg))?

Question

Do you need two basics to get one stage 1 or just one basic to get one stage 1? And do you need to use a trainer card?

Answer 1

No...
All you have to do is to put the Stage 1 card on top of the basic card / stage 2 card on top of the stage 1.

There is a trainer card, Rare Candy, that lets you skip evolutions, allowing you to had from basic to stage 2, but that's unnecessary info.

Source: Experience