The standard 10 gallon tank I get here is 20 inches front, around 10 deep and 12 high. When I was new at this, I thought that was big, and regularly kept way way too many fish in them. As I got older, I overstocked larger tanks. It took me a while to get my head around the need to ease up.
@elephantnose3334 seems young, and I suspect feels that fascination for all the amazing fish we can see in this hobby. I think it's perfectly natural to overstock a tank, but it isn't workable or fair to the fish. When I was in my early teens, every time I made a few bucks painting, cutting grass or dragging golf carts around for drunks, I would head straight to the aquarium store and get more tetras than I had room for. My friends would be out buying drugs and wrecking their health, and I'd be out buying silvertip tetras for my 5 gallon.
Eventually, I met an elderly lfs owner who had been my grandfather's fish seller, and he set me straight as far as stocking goes. It really annoyed me. Most of my fish lived about 6 months, after all. I begrudgingly tried his way and 10 years later, still had a Cory from his store. It's a tough stage in fishkeeping to go through, because we get excited about the choices out there, and really like fish if we bother posting here. You want to see and get to know everything.
I was fortunate because my relatives all seemed to have unused tanks they gave me, and my Dad built a wall rack in my room and patched all the leaks in the old aquariums.
The OP got some standard but not good advice and is overstocked. Lots of water changes and no new additions are the only way forward, if you still live with your parents and don't have Uncles and Aunts hauling dusty, web filled tanks out of their back sheds for you.