>>6277147It's alright, fair mistake to make if you're new. Bandai owns the Gundam franchise pretty much. The license gets lent out to other companies to make licensed goods sometimes, but when it comes to toys and model kits, Bandai is pretty much the only one.
You pretty much have two main options:
1) Model kits (Gunpla). There is a HUGE selection here, in various price ranges, sizes, and complexities, and like the previous anon said, they're surprisingly cheap for what they are. Plus, the building itself is really fun. If you're interested, look for our Gunpla general thread and read up on it there.
2) Robot Damashii. These are about 6" tall prebuilt and painted action figures. These are good if you don't want to put any effort in, but they cost more and the selection is much smaller. They usually pose better than the kits.
There are other smaller options in between, but those are the two big choices.