20 gallon planted tank. Am I overstocked?

The tetras, guppies, corys and shrimp are the only ones suitable for that tank size. I'm concerned though the tetras and guppies will not get along.
However your loaches prefer a much larger tank 50g+ and a larger group
Also the rams are more suitable for 30gallons but idk. It's possible to keep them in a 20 long but I'm pretty sure all together that group will not work.

I am in the process of a similar tank. Same dimensions, no live plants, 6 blk skirt tetras, 4 julii corys. Wanted to add a bolivian ram and am interested in what you ended up doing and how it's going?

Cheers
DTB