Shrimp and goldfish are not going to mix well. You will be feeding the goldfish at some point. Gold fish and plants is another problem as well. I've never kept goldfish, but I've read they eat almost anything.
As far as building the water. Simply get CaSO4, MgSO4 and potassium carbonate. You will add these in various amounts to set a GH and KH.
Ignore pH, and focus on KH. If a particular livestock likes xdKH, then you will set that amount. PH is irrelevant.
https://greenleafaquariums.com/products/calcium-sulfate-caso4-1lb-bag.html
https://greenleafaquariums.com/products/magnesium-sulfate-mgso4-1lb-bag.html
Limited-time deal: CellarScience - AD640LB Potassium Carbonate (lb) https://a.co/d/h4LYw8Z