Hi Joyce!
You got some seriously TERRIBLE advice from your pool store.
If your pH is high, and is trending high, the LAST thing you should do is raise Total Alkalinity. And the stuff they sold you to raise it? It's Baking Soda, in a fancy, expensive box. Sometimes they list the ingredient as "Sodium Hydrogen Carbonate" but that's just another name for Sodium Bicarb...baking soda. Sometimes it's called Citrocarbonate...same stuff.

The BEST shock is simplest: plain unscented Bleach, the stronger the better. Or, Liquid Chlorine which is nothing more than double strength bleach.

Dry acid's OK to lower pH, but I wouldn't mess with T/A yet unless your pH won't stay at a level. Generally, if you notice pH rising, a lower T/A is better, and if it's always dropping, a higher T/A can help.

I think you're back to basics: Shock your pool and keep it shocked until it's clear, using bleach.

Or, given your CURRENT numbers, if you have them, simple Tri-chlor pucks in a floater (not the ones with copper) can help temporarily. It will raise your chlorine level, add stabilizer, and is VERY acidic, lowering your pH, addressing 3 issues at once.

But nothing works without lots of testing.