It's not hard to do. I've had mine going for more nearly four years now. There are plenty of instructions on the net. This one is decent but, really, all you need to do is mix some flour and water (equal amounts by weight), and then replenish it every day by discarding about ⅔ of it and replacing the removed starter with more flour and water at 100% hydration. Do that for a week or so, and you'll have an active starter.
https://foodgeek.dk/en/make-your-own-sourdough-starter-recipe/
Once the starter is established, you need to feed it only once a week. Discard ⅔ of the of the starter each week, and replenish with 100% hydration fresh dough. Let it rise for two or three hours, then stick it in the fridge. It'll survive there quite happily for the entire week. That's basically a maintenance schedule that will keep the starter alive indefinitely. And it keeps it alive at reasonable cost. You need about 50 g of flour per week, which is affordable. If you feed it every day (or even twice a day, as some people suggest), you'll be spending a fortune in flour over a year.
After a while, you may notice that the starter smells a bit like acetone (nail polish). That's normal if you feed it only once a week. Before baking, feed the starter twice, once two days in advance, and a second time one day in advance. That way, you get a nice active and lively starter that doesn't smell like nail polish. Having a really active starter makes a big difference when it comes to baking bread.
When mixing the starter, be sure to stir it vigorously so some air gets mixed into the dough. The yeasts and bacteria need oxygen, so whipping some air into the starter gives them a leg up.
My starter lives in an ordinary glass jar. After a few weeks, the jar gets sort of grotty, with bits of dried dough around the sides. When it starts looking too bad, I just empty out the starter, clean the jar, and put ⅓ starter back into the jar plus, ⅔ of 100% hydration dough.