It's incredibly easy to do if 당신 have a tablet and a program called Paint Tool SAI, but if 당신 don't have either one of those, 당신 may have a difficult time.
Now, 당신 can
try to do it on MS Paint, but it will be
extremely difficult and 당신 probably won't have much luck if you're inexperienced with doing so, especially if you're using a mouse.
당신 best bet is to download a program called GIMP that 당신 can download from their website
link. It may look pretty confusing, but it's actually a very useful program to use.
Now there are several different ways of creating lineart with GIMP, and instead of trying to explain all of these ways to do it myself, I'll link 당신 to a few 유튜브 tutorials, which are actually extremely useful and detailed.
link link link I hope all this works in your advantage and I hope to have helped you. Good luck and have fun!~
link link