Thank you for the answer!
I’m definitely into the old school method of cell animation, I want to paint all the frames - my first test is here. Most of the recommended software is vector based, not what I seek. PAP is nice for learning basics of the movement, but does not offer real painting on a frame (cell). Probably TVPaint will judging by tutorials on-line, I’ll give it a try one day, don’t want to ruing the trial version ATM, when my animation is not ready enough and I need to take care of another projects first.
3D art seems to be the future so I’ll probably learn it one day, but want to get better in 2D first, as it’s what I enjoy the most. Yet for making animation 3D might be a better solution, too.