Nice, I like a good sourdough.
I tried to make my own sourdough starter a couple of years ago. Kept going for 2 weeks but nothing came from it, except from stinking up the kitchen
I had one that didn't take.
I think the key for mine was keeping less of the discard (which I hated, so wasteful!)
What worked for me;
1 litre kilner jar, lid loosely closed (i.e. without the clip fastened). Weigh the jar and note the weight before adding anything.
80g water
50g strong white flour
50g wholemeal flour
Mix at 8am, leave on kitchen counter.
Next day and following days
Pour off as much of the mixture as will pour easily from the jar. You want no more than 50g of the mixture left (and you've weighed the jar, so know how much this is). I've seen plenty of recommendations for keeping 10g.
Add 80g water, mix with what's already in the jar. Add 50g strong white flour & 50g wholemeal, mix into the starter/water mix thoroughly.
Marking the jar with a rubber band (the level of the starter/flour/water mix after "feeding") is a good tip. Mine took slightly more than two weeks to get going, iirc, but now is reliably "doubling and bubbling".
Once the starter's underway, it needs the same feeding routine every day, if you keep it at room temperature. It will go a week between feeds if you keep it in the fridge (bring it out before you want to bake & give it two feeds before baking) or indefinitely if you freeze it. Try not to change flours (or if you do, give it chance to get used to the new mix).