I usually eat inb4 the workout cause ive realized how much the energy difference does, and then id prob look at how many calories you need a day to grow if thats your goal.
And each workout dont just do 1 muscle group, do 2 every workout, so if u doing biceps, you do back too, chest, you do tricpes too and so on
During workout you should try to vary a lot, shock ur muscles, do supersets and finish with an exercise that you can do until u cant anymore, so start with bench, then incline, then whichever you prefer, then dumbell bench / incline / some push ups inbetween the exercises, dont rest for more than a min or 2 tops between. And depending on which kind of muscle you looking to grow you either do more reps with lower weights or less reps with higher reps.
Afterwards you should also eat something, protein shake if you once again are looking to grow, if not a snack or something high protein is sufficient.
And most important, Sleep.