Autodesk sketchbook used to cost money but now they're offering it for free. I don't really like the layout but it's free so I think it's worth just trying out to see if it's your thing.
https://sketchbook.com/
If you're willing to fork over some money, Clip Studio Paint was my program while I did art. It's got a lot of features
https://www.clipstudio.net/en
It goes on sale a lot if you're willing to wait for the sales. Plus it's got a free trial if you just want to test it.