bench press and working on your triceps will help your pushup output
if you workout weekly, you should get to a point where you don't get bad sore muscles anymore. just alternate pecs/triceps one day, biceps/abs/legs another day
i don't lift weights anymore, but when i first started at 14, i bench pressed everyday. (4-5 days a week) i was 5'6", weighed about 120 lbs, maxed out at about 55 lbs on the bench. by the time I was out of highschool I weighed about 155 lbs, and maxed out at 295 on the bench. when i first tested myself on diamond pushups, i did 77. the second time I did 124 diamonds. never tried again after that but i'm confident I would've done at least 200. i did 22 pull ups, only tried that once and i used to do bar dips after every pec work out. I'd do like a set of 60, then 40, then 30
i never took any suppliments, never liked doing that but that's just me