What is the best way to approach a girl to let her know u love her

Just be sweet with her. And be courageous! Compliment her, smile at her, make her feel special by being by her side, make her laugh, etc. And make her feel safe and have her know that you will be there for anything. Tell her that she can always count on you. :)

Wait for a time when you're both calm and tell her by surprise! As corny as it sounds, look into her eyes and tell her so she knows you're serious. Hold her in your arms, tell her she's beautiful, tell her you appreciate her being there with you! Girls love feeling protected and comforted ;)

Make sure the two of you are alone. Or at least alone enough not to be overheard. Then ask her if she knows she is beautiful. We always tend to fall for that one. Hugging her when you have to tell her goodbye and whispering it to her then is always good. It's best to keep it between you two.