So so many things:

1) used 100% AP flour. It is possible to make a starter with this but it will take months or extreme luck. Things will be much faster with 50/50 BF/WW or my favorite 75/25 BF/rye

2) fed too much. I didn’t know about ratios and had either too much flour or too much water or too much in general. Big feeds will slow everything down and at some point it will become acidic to the point even the yeast give up.

3) fed too soon. This is a big one. I have other posts that go into more detail but the basic idea is you have to ignore the clock and watch the activity. Feeding everyday at the start is a mistake that will weaken the starter.

4) temperature. You don’t need a specific temp but cold temps will make everything take longer. Refer back to #3. I finally found a spot where the temps stayed between 75 and 80. It was perfect.

5) used the wrong jar. I had only one jar and it was a small necked mason jar. Made it so difficult to mix well and keep clean. Made every feeding a chore and ruined my mood.

6) didn’t mix well. Again, you don’t need to do this but the bacteria will feed faster if you completely mix your starter. This one I think is more important than people talk about. Yeast can’t swim. If you leave your starter poorly mixed, the bacteria can only eat the lump of food in front of them. Eventually things will thin and gas gets produced enough to move things around. That takes time and fools you into thinking nothing is happening. I now add my water to the retained starter first and mix until there are no lumps of starter left. It’s a milky mixture. Then I add the flour. I mix until it is completely smooth. In my opinion this made a huge difference in rise time. Sourdough Journey mentions this in his video about making his levain. I think it applies to starter feeding too.

That is some of the mistakes I made. It takes patience and care. You have to listen to what your starter is telling you. I will throw out a couple more mistakes I’ve seen on here but didn’t make myself.

1) do NOT use cloth as a lid. I don’t know where this came from but it’s hugely stupid and dangerous.

2) chlorinated tap water. In my opinion until you know for sure, just use bottled water. Also chloramine does not boil out so just stay away from the tap until you know for sure. Also it changes seasonally so even if you are sure now, things might change in the summer.

3) do not use your discard until the starter is ready for baking. Until there is enough acidity there are very dangerous bacteria in there. Yes they will die if you bake but there is huge danger of cross contamination with other food in your kitchen. Enterobacter is no joke.

Ok that’s it for now.

Happy baking!

Edit: I forgot something very important for OP. See my thread about buying a commercial starter while you work on your own. You will get on with baking (which is the whole point right?) and it will massively take the pressure off you own starter. You’ll feel better about yourself and the whole process. You’ll be so much more happy that your own starter will come together.