My Community Tank Problems

Well u i hav a 20 gallon tank with 14 fish
4 fancy guppies
1 angelfish
2 mollies
2 fish tat i don't know what they r called
3 Neons
and 2 tat eat things off the rocks at the bottom

I'm new so i hav many problems
-the tank is foggy and i hav a 30 gallon filter but it doesnt get much cleaner...why??
-how many times do i feed them cuz i dont wanna overfeed them and get the tank dirtier then it already is?
-the angelfish is getting a little agressive with the neons....again why?
-the neons dont eat any food i give them...wat should i feed them?

Ok if i get another problem ill ask again in this post

 

One, you are way overstocked.
Two, the angelfish is getting agressive because neons will nip his fins and he will nip thier fins, they're not at all compatible.
Three, what are your readings?
Four, are you vacumming the gravel, doing water changes, and how often
Five, feed them 2-3 times a day and only as much as they all can eat in about 3 minutes.
Six, can you describe your unknown fish?

 

Neon tetras are the natural pray of angelfish in the wild so don't be too surprised if they start disappearing.