You encourage demand feeds.... Let's the urine and weight gain to the guide to estimate the feeds quantity. If the baby is paying good quantity of urine, then feeds are adequate... Make sure you are using proper dilution while making feeds as instructed on the box

There is no fixed time to feed...on an average child might take 8-10 feeds per day. Feed is usually 30-40ml per feed. And passing stool after feed is also normal for the child

Ideally ,if baby was born full term, 30-50 ml feels are ok, depending on how much baby wants. 250 gm can finish as early as 2-3 days also, it’s on demand feeding, although crying doesn’t always mean hunger. Infants can be fed 2 hrly or 3 hrly. Both are ok and may be followed, but follow either one, don’t mix them both Also, 10 mins of good burping is necessary after each feed.

Consult with Pediatrician physically for further evaluation and treatment