That's no problem at all! Here I couldn't get any specialized betta foods, so Bruce has been eating flakes, crisps and granules for tropical fish
And a lot of freeze-dried and frozen blood worms, they're naturally carnivores so I try to match his needs and give him bloodworms almost every day
About the plants, Dragonii covered it, I've got these two kinds myself
Kept them successfully with the most hungry goldfish on earth. Anubias come in three sizes, there's Dwarf Anubias, that grows like a little cute carpet on the tank floor/wood, Barter's Anubias, which is sort of middle-sized, and last Giant Anubias, which will grow really high and nice!
(But I can't find any Giant Anubias anymore :'''c) I've also heard that Vallisneria works, but I'm not entirely sure.
If you can find one, an Onion Plant would be perfection! It's usually kept with herbivorous fish
Both Anubias and Java Fern have that kind of roots that rather than growing under the substrate, they grab pieces of wood or rock and grow on that, so if you could, it would be a really beautiful idea to stick them with some transparent fishing line to a piece of bogwood or a nice rock
I had one drill the roots straight through one of my pebbles...