Photoshop

The only tutorial I can give you. This is a tip. Do not install photoshop above 2019.

If I'm being honest you should plan your designs and then learn how to make what you have in your mind logically bit by bit. Google how to achieve each little bit at a time because your wasting your time if your learning about tools you will never use, only learn the thing which are relevant to your work that way you become more efficient more quickly.

Try Draw with jazza! If you are into painting and animation.

There's heaps on youtube, maybe too many, try and be specific in your search

Beyond watching videos its really important to simply keep experimenting with photoshop. Youll get used to it.