If you are getting 10% chlorine at Lowes or H-D for $3.50, that's not a bad price. It may actually be 12.5% but they mark it lower to prevent lawsuits.

The reason you weren't given a CC level by the Pool Store and why they said it was 0 is that your FC and TC were the same. TC is total chlorine and TC = FC + CC. This is always even if your test strip says TC is lower than FC (which they do!) So if you have two of the 3 measures you can calculate the third. The standard DPD test that can measure only up to about 15ppm measures FC and TC. So CC=TC-FC. The far more useful FAS-DPD test (which is in the kit you ordered) measures up to 50ppm and measures FC and CC instead. Here TC = FC + CC.

Meanwhile there's nothing I can add to Jan and Lisa's advice on what to do. Good luck!

Carl