Hi Lindy
My wife and I have been to Tossa every September for nearly twenty years but never this early but I would hope that most places will have opened up at easter though I would think that restruants will take varying nights off.
Tossa is a quite and safe place to visit and my advice is your party should and go explore the new towm. old town and vila vela day and night we are now in our mid sixties and have never felt uncomfortable wandering the streets.
I would strongly recomend that you visit tossacostabrave.com website run by Sarah and full of members with a love of Tossa where there are sections dealing with all aspects and recomendations for a visit.
We love Tossa and like to spend time in local bars rather than "british bars" but we enjoyed a few nights out in both so I do not like to post must go places but look out for Cafe Berlin in the back streets at rear of church (have a look at the menu and prices0 I am sure you will want to try this very popular restruant.
My favourite locals bar is Bar Joseph in a small street behind prom. at Vila Vela and of beach, in Sept full of visitors and dour catalans.
Remenber visit the above website and go EXPLORE with your freinds I am sure you will enjoy Tossa de Mar.
regards
Parsfan