I'm not a lesbien or bi but I have a lot of friends who are. It's obviously much more difficult for you to find partners but on the plus side, you have a lot more support out there to help you. If there's one around you join a LBGTQ society. Go to gay nights at clubs, or just gay clubs. You'll get the hang of it, your gaydar will improve. It's no different to sending signals to someone of the opposite gender, you just flirt.