Hi, @nurfay!
I encourage you to try making sourdough so that you can then make bread with this wonderful leaven that will keep your digestive system in optimal condition.
As for the presentation of the sourdough I suggest you use strong or whole wheat flour with a bit of rye flour, as the latter is a bit sweet and makes the sourdough ferment faster. As for its preparation you should only use the same amount of flour and water. That is to say, if you use 30 gms of flour, then 30 gms of water. I make it by eye by the way because I already have some experience, but at the beginning I used equal amounts. On Youtube you can find many videos with the step by step of this process.
I'm glad you liked this recipe and thank you very much for your visit and support.