I think most folks will tell you that if you're talking about Adobe Photoshop and Corel Paint Shop or Painter or whatever, then you have the tools you need, now you just need to learn to use them. Both are pretty powerful and probably for that reason, not easy to learn. It is nearly impossible for software like this to be user friendly or at least, not as user friendly as a pencil and paper. You're dealing with hundreds of features, most of which can be applied multiple ways and tools that can all be customized. That said, every artist you see around here and any digital artist anywhere has probably used one or both of these programs, or uses them regularly. I'd guess a majority of those have had formal training. The self taught crowd will probably have some stories of frustration from their early days to tell you. I'd also add that there are a couple trial versions or scaled down versions of both programs. If you have them, they will be missing features and that could make following tutorials more difficult or just not allow you to do some things. The bottom line is that everyone knows PS is the industry standard in 2D digital art and is regularly applied to 3D art as well. If you have it in a complete version, I'd suggest doing all you can to learn it. There is another thread
https://lateral-g.net/forums/showthread.php4?t=16283 that has some good tips and I have no doubt other threads like it that have been started in the past. I always recommend
www.deviantart.com because there is a damn near infinite wealth of information there concerning digital art and PS especially - Corel as well.