Brickladyt, your HTH test kit will get you by, however, I don't think enough people emphasized the actual, absolute need for a TFT-100 (or Taylor 2006) test kit. One of those kits WILL be what saves you the money. I know, I bit the bullet for the big Taylor 2006C kit (get it from Amazon), but it gives me absolute, foolproof knowledge of the chemical state of my pool. I have been using BBB for a few years now, but this year I threw out my Intex salt water thing (because the salt was damaging my heater) and am using only bleach in my pool. So far, best pool experience ever using only bleach.
On to your issues......I would hesitate adding anything with stabilizer (CYA) in it. If your pool store actually was telling you the truth and you did have CYA in your pool.....well please retest. If you have to increase CYA, then carefully use up the shock (that should have CYA on the label, right?) you already have. Next year, just buy "Stabilizer" and use it instead of something with a bunch of Crud fillers in it. (hint: get a 4 pound pail from Amazon). Again, using the "Pool Calculator" to give you the proper numbers of how much to add. I will caution you, if you still feel uncomfortable using the Pool Calculator. Give yourself a bigger pool on the calculator, see how it changes things, then go back to your size and really get used to using it and seeing what it does. I suggest you either get a tablet to write down your testing results and chemical usage or create a spreadsheet on your computer to monitor your pool.
Now, let's look to next year. If you go with either the same pool or decide to get a bigger one you should only need three more things: your GOOD test kit, 2 or 3 bottles of regular Clorox, and stabilizer (expensive liquid or dry powder), that's it. Please keep that pool covered if you can, that will keep your chlorine from being burned off from the sun and keep a bunch of Crud out of the pool that you will have to filter.
Speaking of filters, when you get tired of Intex filters, search for the "Unicell" brand size of your filter. Buy two: one will be in your pump/filter and the other will be soaking in a big covered 5 gallon pail with some bleach and TSP in it. when you need to change filters, rinse off the one that was soaking and put the "used" one in the bucket with a little more bleach for good measure. That will pay for itself within a very short time. Unicell filters for our purposes will last the entire season and probably two.....at least I am on season two of one of mine.....
Good luck.
Bob E.