In the summer coaches can go to anything. In NJ out of season coaches can only attend lifting, conditioning, or other sport activities. So a football coach could not supervise a QB throwing to his WRs running routes, with a football, during the winter or spring, or a lacrosse coach can not supervise kids playing catch in lacrosse during the fall or winter.
Coaches can attend events their players are at, if fans are present, but can not actively coach in the sport.
For example I would watch my kids play winter league lacrosse, but would have to have an alumni on the side line coaching them.
When I coached high school football we had a place for footballs to be out in the weight room, but could not tell kids to throw with them.