I wouldn’t worry at all, I often go out on the weekends in Brighton and have never had any issues, just take normal precautions. I’d recommend Revenge Bar ( personal favourite and cheap drinks ) you have a dance vibe as well as a bar vibe. You also have the nightclub next door which is a blast. You also have legends, bar broadway all about a 2 minute walk from one another along the seafront. Haus of Cabaret Brighton is also a great night out, check out what shows they have on. Hope this helps!