how to find textures/images? (aura mastery cast bar)

[Drool]

hello,

im looking for the aura mastery cast bar border. how do i even find specific textures?

heres a shoop of what im planing to do:



i hope someone can help me out, i really dont know where to look for - im relatively new to this :3

thanks!
- Drool

/edit nvm found it