The setting is Ponyville some 8-10 years' equivalency in the future (more or less). Stories are mostly about the Cakes, but also a bit about future-Equestria in general!
Everything here is SFW, feel free to read it with your kids/nieces/nephews/other small children in your care.
Thanks for reading!
tl;dr about canon: some elements may be grandfathered in from pre-season 4 stories, and therefore may not be 100% canon-compliant. This is because Slice has been going on long enough that it's hit a point where certain things may be too difficult to change, not because I have any issues with the show itself.
That aside, this comic is based purely on the show itself. Other elements might sneak in if I like them, but otherwise it's strictly show-canon. Something that shows up only in the comics/trading cards/toys/books does not necessarily apply here.