How do I become closer to G-d?

Average Teen, ethnic Jewish.

For basically my entire life I’ve been fairly agnostic and never done things like pray, follow Halakha or keep Kosher, on several occasions I’ve accidentally broken Yom Kippur fasts aswell. Apart from celebrating holidays with my family such as Rosh Hashanah, Hanukkah, Pesach, etc. I haven’t really done anything that would make me a better Jew. I’ve recently grown stronger in faith and everyday my belief in G-d increases, and I realize that I’ve sinned my entire life, how can I become closer to G-d?