Stocking ideas, pleaseee?

I'd actually advise you to get rid of your molly. Mollies should be in groups of 3 or more, they also need a minimum tank of 30 gallons. Mollies, especially black mollies, are a brackish water fish as well, keeping them in freshwater will shorten their lifespan and ruin their immune system making them more susceptible to diseases, parasites, bacterial infections and other sicknesses.

Most tetras actually need 20 gallon or more, so I don't recommend keeping them in your tank.

If you're looking for schooling fish you could get celestial pearl danios, dwarf rasboras, lampeye killifish, gardneri killifish, ember tetras, or pygmy cories.

Other options would be endlers, same sex guppies, sparkling gourami or honey gourami.

African dwarf frogs are a good choice, they are social and should be kept in at least groups of 3's. A few things to keep in mind, they are carnivores so no flakes, no pellets and no freeze-dried foods. Only live or frozen foods, they are also very slow getting their food, it's easy for them to starve to death because other fish are eating their food. So feeding them with a small eye dropper or a long pair of tweezers would be ideal.

You can use websites like www.aqadvisor.com as a guide line for stocking your aquarium. However remember it's just as a guide line and not to be taken too seriously.

tetras would be nice but you must know that 6 or more is requiered when having tetras and for that amount of fish and the amount of fish you have in your tank I would say that if you want to get tetras don't think about getting any other fish until you ether get rid of your other fish or get rid of the tetras.