Well, firstly I would keep your love for him a secret for a while and see whether you can talk to him and see if he is interested and go on a few dates and hopefully start to be in a relationship...... If he isn't interested then you will not feel bad cos you haven't said anything about your love. Saying it too quickly will scare him off or cause a lot of hurt and embarrassment.
If you end up together and it lasts and he ends up saying those three words and you end up married right then you can say that you loved him at first sight or first time you spend time with each other and it was the best date you ever had etc.
Till then, keep this love to yourself to protect your heart....and hopefully you will start to date if it end up after chatting with him etc he likes you...you can always ask him out if that, he is interested but keep this love to yourself for now. Protecting the heart is important.