Beta fish care

Hello all!
I have not had fish for quite a while, and am definitely rusty.

However while my partner and I were getting food for my dog, we found a poorly female beta fish that was missing an eyeball that was floating in the cup with her, and she was very distressed. I convinced the store to sell me the fish instead of taking it out back to die, and I bought Supplies for her and setup the tank when we got home. I got her a 20 gallon tank, a live plant, some betta buddy starter bulbs that are supposed to grow I guess, and some decor. I know the tank isn’t going to be cycled for a few weeks, so I have been doing frequent water changes since I got her a few days ago. She seems to be doing well! I know it would have been ideal to have the tank cycled beforehand and whatnot, but I guess I’m just looking for tips on what I can do now, how to care for a betta, and if there are any fish I could eventually introduce to the tank once it is cycled? And what live plants are a good addition so he can have more hidey places? The tank was obviously just quickly thrown together.
my partner and I have fondly named her Wink/Winky/Winks lol
Thanks in advance!

 

java moss! thrives in low light, and my betta loves to hide in/under it. the only con i'd say, is that it gets everywhere and you'll have to scoop floaties out frequently. I also have a new anubias nana! it's a small, leafy aquatic plant that also is easy to care for and thrives in low light. these make good mattresses for sleepy betta

 

She's beautiful! Hornwort and amazon sword are both good. They both grow relatively quickly and are fun for the fish to swim in. Floating plants like Amazon frogbit are good, because the plants create shadier spots (bettas like lower light levels) and also have fun long roots.

I also recommend purchasing some tannin-leeching products, such as indian almond leaves or alder cones. Tannins help to reduce stress and can have antibacterial properties (which will be really important are her eye socket continues to heal). It'll stain your water yellow/orange/brown (depending on how dark you want to go), but it's great for them and helps the green color of the plants really pop.

 

Thank you guys for your responses so far!
Here’s another photo of her tank
Also, I bought small beta pellets and I have some old repashy soilent green gel food that is still good. Is this okay?

 

20gl is a great tank size for a Betta. Warm clean (conditioned) water is the best thing you can do for your pretty little girl.
A Betta hammock will be appreciated, and may be a betta log so she can hide if she wants to until plant cover is more plentiful.
A good frozen blood worm here and there, and frozen daphnia will keep her happy.

 

The betta hammock is a great idea, thanks!

 

Some great hardy plants are anubias and elodea. The elodea can either be free floated or planted. In addition to more live plants I also recommend a float betta log. My betta is obsessed with his. You could also add caves/tubes for them to swim through, bettas love interacting with their environment.