Stocking advice?

(1st pic is current setup) This is my 1st tank, I've had it for about 8 months and I've learned a lot since then. Started out by taking advice from pet store employees and quickly learned not to do that.

After starting with weird stock, rehoming some fish and some passing away, I am left with some weird stock. The tank is 20gal.

I have: 1 female betta (a friend gave her and 2 other females to me when moving, I rehomed the other 2, but she's so beautiful and docile, i couldnt rehome her) 1 bronze corydora (got him 4 friends that all died within 48 hours of being here, pet store refunded me) - im aware that he needs friends and a long tank 2 female guppies (had 2 male endlers and 3 females but 2 died of a weird disease and the others were killed by the bettas I used to have in there) 3 female platys (I think they're all female but not 100% sure) 3 african dwarf frogs - I'm aware that this tank is not suitable for them at all, getting them a new setup

I'm getting a 10gal long from my dad next week, I was thinking to put the frogs and get a few more Cory's and put them in there. Then, get a male platy and male betta for the hexagon tank. Do I need more tanks to properly accommodate everyone?

Would be ideal if I could get another tank for corys and betta, and keep the frogs in a species only tank. Just have to figure out where to put it. What would you do if you were me? I'm attached to these creatures and don't want to start over, but I also want them to have a good life

I also have a 4 gallon tank with a divider that currently has my rabbit snail and her 2 babies on one side, the other side is empty and I was thinking of getting shrimp to put in there