You can still replicate this painting, just don’t expect the exact same behaviour of the brush and the same effects. Put the correct colors in correct places, and it will already look ok. And in the future you’ll learn more techniques and how to use specific brushes etc. and you’ll be able to get the much nicer effects. For paintings like that I’d suggest using some nice textured brushes, not the simple circle one, because textured brushes will look good without much effort (textured = chalk brushes, pencil brushes, acrylic brushes, bristle brushes, everything that is not too simple but it’s generic enough you could use it for the whole painting).
I recently became a fan of a specific brush from a Ramon’s new brush set: Pink flowers on a hill and there is also wojtryb’s brush pack you might be interested in: Version 6.0 of wojtryb's "Wont teach you to draw" brushpack relased and of course brushes that are already included in Krita, you can search for them “RGBA” in the search box. But don’t spend too much time on this: choose one or two, max three brushes you like the effects of and you think you can paint everything with it, and then forget about all others. (Best way: assign the nicest brush to a new tag; then assign this tag to other nice brushes; and then switch Brush Presets docker to that tag).