So I was just thinking about implementing ads into my game, but I just need to know, how do I get money, am I supposed to register somewhere or what?
Point 1 in the manual: https://www.scirra.com/manual/184/admob
Develop games in your browser. Powerful, performant & highly capable.
—, how do I phrase it so that a banner ad shows on start of a layout
— just search for AdMob tutorials. It's really self explanatory so you can also simply check AdMob object functions.
AdMob -> Show banner