unless it's an age-restricted night event, the minors shouldn't be excluded from the bar. They just can't order drinks (so get someone else to do it if it's a problem).
if you're all out of ideas on what's fun to do as a group during o week, cub scouts and jinja safari are playing in the quad on wed late arvo/early evening so just go to that and watch the bands and dance or stand there awkwardly. You don't even have to socialise if that's going to be a problem. Both bands have a fairly simple beat that's easy to nod along to.