Welcome! That's great you've picked up the guitar!

I started learning last July and recall that learning songs with just two or three chords was very helpful in the beginning. Sure, I would drill myself on the chord shapes over and over but I didn't really start committing them to memory until I started playing actual songs. Lisa has a lot of these embedded into the funadmentals lessons and there are a lot of online rescources and books you can find that just use three chords. Just an idea!

Maybe someone else can help on how to not hit the other strings. That may just be something that comes with practice. You can also try doing a search in the forum for anyone else who may have had the same problem.