Fot the tips about security and robberies, please check online. My perception was that if you go without phone and credit cards, but with swim suit with zip keeping with you few cas, you should be fine.
For the rest, go there late in the afternoon before the sunset. Walk on the beach and see all the brazilians playing football listening to samba music. Go to La murete to admire the violet and orangish sunset drinking a good caipirinha.
The morning, check when is the sunrise e go there... It is the most beautiful fire in the sky i have ever see. Maybe go in front of posto 5 where there are always organized group of people doing cardio so you are not alone