There is no “how to”. You just wear it. All you have to do is try it on before you make a decision. Make sure you like the way you look, including from the back. Make sure you can bend over and squat without it showing anything you don’t want showing. Make sure it is not too big. A bikini that is too small is always better than one that is too big.
All in all, you can wear whatever you want to! Confidence is what will make anyone look good.