This was a previous post i made about angelfish
Here is my plan. Move all your platies to that tank. Use platies to cycle and you can keep them there. Then maybe get a few more female platies. Next, look at the corys, find one that you like, and get around 4-6 of them. Next, you can find some algae eaters, maybe like 3-4 otos or one brittlenose pleco. And last but not least, get Angelfish.
THe reason behind having platies in this tank is to breed them. Angelfish love other fishes fry and who's better at making babies than platies. Getting cories is also good as they can clean the bottom of your tank as well as looking very cute and funny. Getting an algae eater is self explanatory. And Angelfish are BEAUTIFUL fish, plus they do great in a higher type tank since they are normally taller instead of wide and are slow swimmers. Also Angelfish look great in a planted aquarium. You might have some room in that tank for more things but make sure they are community type fish. No newts, no bettas, and no goldfish.
I would not reccomend sharks, they arent easy to take care of, most of them grow huge, and they should have a long aquarium rather than a tall one.