Is there a way to import sprites or tiles

[AlexK]

Hi, @Zoki. Welcome!

The short answer to this is “no.”

.jpg as sprite?

There is currently no easy way to import images into Arcade. This is mostly intentional to (1) encourage creation of art skills rather than internet search skills (2) avoid all kinds of bad things you find on internet.

The longer answer: You can build your own sprite packs, although I have not yet tried this myself. https://github.com/microsoft/pxt-arcade/blob/master/README.md (Scroll down a bit for the information on creating a sprite pack.)