From what I know...which isn’t a lot...you need to invest time and patience in your ‘starter’...if you make it into a hobby, then you’ll have started that has been fermented for months on end.
Netflix has The Chef Show...with Jon Favreau and Chef Roy Choi...it’s amazing. The episode with Sam Raimi has half of the show dedicated to making sourdough.
I started a few months back. It is a labour of love for sure. If you go to Youtube there are a couple of people I follow that can help. One is "foolproof baking" and another guy is Joshua Weissman. You have to start by making a proper starter. It takes about a week. You will need a scale ($20 on Amazon)