At both levels, the only sports really worth asking about are football (American) and basketball, at least when looked at on an across-the-board level in terms of national culture. (There may be small regions or individual communities where everyone really gets into soccer, lacrosse, volleyball, etc.) As noted above, it’s sort of variable for high school. In Texas, where I live, high school football is, in fact, a big huge deal. Whole communities bond around the success of their school’s team. Families move so their sons can play for traditionally powerful schools. Players are treated like special beings.
On the basketball side, some places have a reputation as basketball hotbeds (Indiana, for example), and I’ve heard that high school basketball is a really big thing in those places, too.
College football has always been very popular and has become a huge deal to the point of insanity over the past decade or so. Not quite so much the case for college basketball, although the annual championship tournament in March (“March Madness”) is definitely a Thing.
It’s weird that baseball, which to many is THE quintessentially American sport and is certainly one of the three major ones here, doesn’t have much of a serious following at either the high school or college level.
I do have a question about Ireland- maybe this could be applicable elsewhere, too. Background: at my first job (about 20 years ago), our company hired an Irish woman as our receptionist. A friendship developed between her an our accountant, with the two of them getting together socially outside of work on a semi-regular basis. At some point, the receptionist’s parents were coming from Ireland for a visit, so the accountant offered to have them all over to her house for dinner while the parents were here. As the day approached, the accountant told her what she was planning to serve. When she mentioned corn on the cob, the receptionist looked horrified and asked her to please find something else.
Apparently the concern was that, to the Irish parents, corn on the cob was something that you feed to pigs, and the receptionist was afraid that they would be terribly offended at being offered livestock food. So… is this an Irish thing, or was this just a weird hangup the parents had? 'Cause, corn on the cob is GREAT, and I feel existential pity for anyone who would refuse to partake.