IF you want the last word on how to make a sourdough starter, here it is: (skipped over the technical stuff in part 1).

https://www.thefreshloaf.com/node/10901/pineapple-juice-solution-part-2

Be easier to use whole wheat as rye flour is now hard to come by.

Also, when the time comes, look at ingredients on sack of flour. It will work better if it has malted barley, which is a fermentable sugar. Bread flour from Walmart works.