first timer here

you should start looking for youtube tutorials or finding the manual of your software. The big problem with the digital tools that you need to learn the software at the same time you learn how to draw, this is why many people will tell you that it's better start using pencil.

If you are a hobbist, the software that you will use will no matter that much, but many people prefer photoshop (it's the industry standar) because it's has a lot of documentation. so the only thing that I can say you it's try many programs until you find the one you like it.

Is not a good book it teaches you how to use krita but it doesn't teach you how to paint