First time Mom

I recently had my baby girl on Sunday 11/12 . I was breast feeding without any worries the first 2 days I stayed at the hospital . I came home today ( the 3rd day) and I feel like she is not getting full the hospital let me feed her with pre made bottle formula and she had no problem eating.

I am wondering if I should continue to try and breast feed or just formula feed. I am honestly getting a little stressed out about it .

I also have breast feed and then gave her a ounce or 2 of bottle after but I don’t know . I’m really confused about the whole thing and what to do.

Also if I do choose to give her formula is there special water I need to prepare and how much formula should I give her? Ahh