You definitely can't do mollies in 8 gallons. You certainly can do a betta or shrimp or both, depending on the betta. One of my bettas eats the shrimp and the rest of them don't bother the shrimp at all. You *might* be able to do a small shoal of 4 or 5 pygmy cories in there.
Probably the best and safest bet would be a betta with either shrimp or nerite snails.
If you want to skip the betta, you could get a few endlers or celestial pearl danios or chili rasboras or sparkling gourami or scarlet badis along with shrimp. Or you could get a dwarf/pea puffer - they are super adorable, but they need to be alone because they will chew on anything and anyone. I have one in a 5 gallon tank, and he is the cutest thing ever. I swear he just moves through the power of thought. I'll be looking into the tank, and he'll just appear in front of my eyes like he uncloaked or something.
Probably the best and safest bet would be a betta with either shrimp or nerite snails.
If you want to skip the betta, you could get a few endlers or celestial pearl danios or chili rasboras or sparkling gourami or scarlet badis along with shrimp. Or you could get a dwarf/pea puffer - they are super adorable, but they need to be alone because they will chew on anything and anyone. I have one in a 5 gallon tank, and he is the cutest thing ever. I swear he just moves through the power of thought. I'll be looking into the tank, and he'll just appear in front of my eyes like he uncloaked or something.