Most shootings at schools are targeted (jilted lover type situations—often these target an adult, not a student; something related to other crime, like beef over drug dealing territory between students) or are coincidences (a shooting otherwise having nothing to do with the school happens to take place on the edge of the parking lot, or something like that). They're not what people usually mean by "school shooting"—though, I mean, obviously they're still not great.
However, even including those, a couple years back I ran the numbers on odds of a kid even being present (not hurt or killed) during any kind of shooting at a school, over a 13-year K-12 school career, and I don't remember the exact figure, but it was low enough that I concluded none of this was worth any real concern on my part at all. And that's assuming shootings at schools are evenly distributed, which I'm sure they're not.
This list says 11 dead and 6 injured in 2023, but I concede that it omits incidents with fewer than 4 dead.