Will knowledge of GM help in working with C2?

I came from RPG Maker which also uses events and I have adapted to C2 pretty quickly.

C2's learning curve is not steep at all if whether you ever worked with event based systems before or not. In the end logic is all that matters really.

I'm using both yoyogames GameMaker and scirra construct 2

the both engines have their pros and cons, I highly recommended if not costly to you, to get them both, you wont regard the decisions, in fact some games can make better using C2, while other will be easier and

faster to create them with GameMaker, nothing against you to use them

both for different games and purposes ;)

C2 so awesome that can make u benefit the tilesets from gamemaker, when you can import gamemaker rooms to C2.