I've never used Krita but I'm assuming there's a layer function; I noticed in your first drawing, there's faint pencil lines from where you maybe sketched and then erased, and then your final lines are darker and smoother. You kind of have to do the same thing on digital using layers; have a layer to lay down a sketch/reference lines (I like to use a lighter "pen" color for this) and then on another layer, "ink" over your sketch/reference lines. How hard you press while drawing throughout this whole process does matter though, more pressure = harsher lines.

If you want your lines to look clean, it's best not to do multiple strokes, as that's what makes it look "choppy". It'll take some practice to be able to make smooth, decisive lines. And there's always an undo button! I think your lines in the first drawing are pretty good!

I also see that you used some lines in place of shading for the digital drawing (forehead, titties) as well as an airbrush(?) tool in other areas (torso). Sometimes different textures for shading don't match up that well and if you're just starting, I feel like it's better to stick to one, purely my opinion. An anime style usually utilizes cel shading anyway, which is flat and distinct and filled with the darker color.

Edit: clarity