Unless you have lots of room and time to spend on the Bettas don't do it.
But, I'll tell you some of the stuff that is needed (I've never bred Bettas so I don't know everything sorry.)
A 10 gallon tank for breeding.
At least 2 5-10 gallon tank for each Betta you are planning to breed from
At least 200 tanks for Betta fry, bear in mind most females will be able to stay in one tank so a 20-30 gallon tank would be good for this. All males need their own tanks.
Live food culture of brine shrimp to feed the fry
A heated room/tank heaters for every tank.
Bloodworms to condition the parents.
Lids for all of the tanks.
There's probably more things that I have forgotten. I'm sure Wildbetta will fill in the rest
Also, I recommend that you get your breeding pair/s from a Betta breeder.