Do i have enough space to add more fish?

I have a 20 gallon high tank with 12 total community fish and I was wondering if I can add any more because I have 3 octo dwarf suckered 2 albino corys 3 peppered corys and 3 marble mollies female and a yellow molly male should I add more fish ?

No. The mollies will breed and you will have lots of baby mollies that will need a home.

Mollies also need hard water (GH above 250ppm and pH above 7.0).
The other fishes you have come from soft water with a GH below 150ppm and a pH around 7.0 or a bit below.

I live in texas so my water is always hard.