Yes I was just writing this!
Having had a long and sometimes trying journey to crack this, I think I might be able to help.
Follow steps 1 and 2 here https://www.bbcgoodfood.com/recipes/sourdough
and then a week down the road when you've got a working starter, I'd switch to this method which Ronott posted on BYC
Sourdough is fairly easy - say's the gal who has let 2 starts go bad in the last 2 years, lol. I had one for over 6 years before this...
What is your fear - maybe i can help.
Is your starter dehydrated?
You can get some great info at: http://www.carlsfriends.net/
Download the PDF brochure - it has some great recipes and tells you how to take care of your starter.
My problem is that I forget it in the fridge for months on end without feeding it and it gets inoculated with bad wild yeasts.
If they could keep a starter going on a wagon train crossing the country, You will be able to do it in your kitchen.