Please advise on my rookie mistakes (video)

Hey all! I started playing tennis 2 weeks ago. Never played on court (no buddy), all I’ve been doing is practicing against the wall for 2 weeks now. I ordered my racket for $30 on Aug 26 from Amazon and 10 balls. It’s such effortless cardio for me (I lost 10 lbs just playing every day) I’d like you to give me some tips what am I doing wrong 1) sometimes I can’t hit the ball with full power 2) I keep hitting the balls with the edge of my racket 3) should I already consider a couch? 4) should I move onto courts? Thanks a lot!