If you stay in the city, the Raddison is nice, centrally located and safe. Across the street is a lovely restaurant, the Smoky Mermaid.
You can do day tours that take you out of the city to the zoo, Altun Ha, Old Belize at Cucumber Bay and the list goes on.
Personally I wouldn't want to base myself in the city, but if its already booked etc. make the most of it.
The wonderful thing about Belize is its indigenous people - enjoy.
As with anywhere be street smart and you will have fun without any trouble.