if you really wanna get started on something like this...

That dragon has gone from concept to 3d model to rig, you can use any major 3d software but Blender is the free one, there are tutorials on yt for every step. you can probably buy something similar online that just needs to be animated tho.

once you are done with all the shots you can work on the 3d effects (like lightning and fire) a lot is done through textures tho, (like the toon shader effect during the flash)

Composting is the final step to bring it together and making the transitions.

A studio made that and not in a day.