You should enrich yourself from all aspects, no matter in study, money or economic status, you should go beyond the object you secretly love, show him your best side, play some tricks yourself, try to create some romance for him and make her feel that you are a safe person. You should make her think that you are a humorous person. If you have these conditions, you should strive for your happiness at once, otherwise you will be old.
If you like him, tell her quickly. Say it with your strength. The most important thing is to let her know that you like her. If you can't catch up with her, bless others!