Do u have to book to get in carraghers bar

The bar does not need reservation but it is better to call them before you go in.

If a match is on try reserve .. if not this place is spacious and not so full when no sport is on

You can call and reserve if you want a table. But, generally, they will have tables open if you get there without a reservation. If there's an event going on, you might not get seated right away. The bar does not need a reservation, though.