There are no stupid questions here. Welcome to AA, petitemonk.
The usual rule of thumb is to feed no more than your fish can eat in 3-5 minutes. I think the danger in overfeeding when they eat everything you give them would be that they might get constipated. Then they get all bloated, sit on the bottom, and they could die.
Hope that helps.
And God said, "Let the waters swarm with fish and other life..." So God created great sea creatures and every sort of fish... And God saw that it was good. Then God blessed them, saying, "Let the fish multiply and fill the oceans..." Genesis 1:20-22