The usual way gone for centuries? So, practice, practice, practice, yes, that has never changed. 
Today you have the freedom to choose to learn only by yourself or with help of a teacher.
But the good thing these days compared with the regiment artists were under in the medieval is, you can choose your teachers freely, or you can rely only on books or videos out of the WWW, especially YouTube has a huge amount of materials to learn of and from. And what you want to paint is absolutely up to you, the âold mastersâ were drilled as if they were to go into a war, they had to do what they were told not what they wanted to do, so have fun, search for things you find interesting and go.
For YouTube, go and use their search bar and try to search for âKrita beginnerâ or other things that are of interest for you.
An excellent series of tutorials for Krita can be found in the channel Blade & Quill from our forum member Corinne @CelticCoco, of course also very good videos can be found in Kritaâs own channel.
And, and that is not a joke, there is a small tutorial series which was made for Kids 35-part Krita course for kids, but I think not only suitable for children, and when you can look over this fact that the intended audience is differently âaddressedâ, then this series can be great for you, especially if you have a learning disability, AHD or things like that, because there you get information in small and good understandable pieces.
BUT, begin with small projects, refine your skills bit by bit, to not disappoint yourself because you canât finish something the way you imagined. It is like in school, first you learn the alphabet, then youâll learn to write some words, and after some years you write an essay, not the other way around.
AND stay away from those who tell you stories of the kind: âyou only need to do this or that, and youâll be a top artist in no timeâ, âyou only need my brush PaintWonder 3000, and you can paint anythingâ, these are fairytales, and especially the last kind is usually a very expensive one for only learning how you got betrayed. Yes, there are some very good tips out there that will make things more easy, and of course you can get good brushes, but especially for Krita the best brushes are free, at least since the âExpansionâ Pack for Krita 5.x can be downloaded for free (and in the resource area of our forum you can find so many more (of different quality)).
But you donât necessarily need to search for other brushes, because even Kritaâs stock brushes are excellent, and perhaps it is better to not confuse oneself with too many choices in the beginning.
I hope you will get a lot more tips from other users too. And do not forget our forum search, which is the small magnifying glass in the upper right of the forum pages and of course not the Krita manual which is an excellent-written guide through the jungle of Krita and describes many things in detail, you can call it directly out of Krita with the shortcut F1.
Michelist