If you wish to build your own drone, you can find most of the stuff at Techblueprint, including the Arduino Compatible Kits. You can even get 3D printer Kit if you’re into doing everything from scratch. If not, and would rather get the finished product first, you can go for them directly there for the drones as well.
There is a lot to learn with Drones, so you may want to start out with smaller ones.
Whatever you decide to do, remember that Techblueprint can help you get started with Arduino with some of its free resources on this blog as well as its detailed one-to-one instructor led courses.
All the best, and Happy “Droning”!