20gallon community tank

[Jeff likes fish]

I am very very new to having fish! Ice had my tank for only a few weeks, my fish seem happy. 1 angelfish 2 mollies 2 platys 1 white skirt 1 Cory cat and 1 pleco. They are not aggressive at all. And seem very healthy with a diet of tropical flakes and brine shrimp. And a algae wafer every other day for the bottom feeders. I have an air line running through the bottom which I poked several holes that created a home made curtain of bubbles which my fish love! I have a lid with two 25 watt blue bulbs a pf 10 whisper tetra filter and a heater for a 10 gallon that has been working perfectly in my 20 just like the filter. All my levels are perfect including temperature. I was wondering if it would okay to add any more fish to my tank! And any suggestions about what fish to get! I am especially fond of the gouramis! Btw the angelglfish is tiny but will be moved to a very large tank ib the future. ( not my tank)