I’m new to playing online and am unclear on what ranks I should be playing against. Do I just keep playing games and eventually OGS will rank me?
With each ranked game you play, OGS will adjust it’s assumption of your rating. After 5 to 15 games it gets sure enought about your rating and the “Provisional rank” will be replaced by your estimated rank.
Judging from your last game, I think you will be placed somewhere between 23k and 17k. Best would be to play in that range until your rank is stable enough.
OGS rating is quite responsive so it will adjust and give it quickly. Rating is mostly useful to get matched with players of your level around, so before that you can come in chat to ask for a game telling how you think your level is, or propose/select game offers.