I’m new to online-go and I was wondering how you become a better rank
Welcome to OGS! You climb the rank (25k→1k, then 1d→7d) by playing games — and winning them.
Don’t sweat about the rank too much though, take it as a pointer that will help you find a game you can enjoy. If you are enjoying the game, you will learn something from it and improve almost effortlessly.
Go ranks are based on statistical chances of winning. https://en.wikipedia.org/wiki/Go_ranks_and_ratings
Only games that are selected as “ranked” are calculated. So best way to rank up is to play a lot and learn new shapes and strategies
In the end the rank is not so important. It will just get you better games where each of the players have around 50% chance of winning that particular game. So it is there to make for better quality games.
Just relax and don’t mind about rank much.
Are you familiar with chess? I believe OGS uses a variation on the elo system and then translates that into kyu dan ranks. So looking up elo on Wikipedia will probably be more relevant than looking up kyu dan ranks.