How to saddle?
In addition to taming, you can also saddle a dragon, for this use a regular horse saddle. Take it in your hands, point it at the dragon and place it with a long tap on the screen.
Dragons can be equipped with netherite armor, place 2×2 netherite bars to create it. After you have armor, you can put it on the dragon in the same way as a saddle, using a long tap on the screen.