In the US, at least, a parent or legal gaurdian must be present for under 21 yr olds to play in a bar/pub. In some states, even then not. Alchohol/licensing laws in the States are very weird.....they vary from state to state and even from town to town.

Get an exact itinerary and then ask each town. Bars/Pubs are almost always the best places to book gigs for money--either up front or for a "tip jar".