Somebody called me? OOOOF, that is soooooome recommendations!
You are smart to question. Lots of people get poolstored over a long period of time before they wake up. Get ready for the red pill...
You don't need to "manage" TA. TA will generally manage itself if you keep your pH in the 7s. When pH rises to 8, reduce it to 7.2. Rince and repeat. Over time your TA will come down on its own.
When you get your test kit, test the TA of your fill water...this may give us a clue on your highish TA.
Post up a full set of results and we'll point you in the right direction.
A Great place to start...Link-->
Pool Care Basics
We don't trust pool store results, they can be wildly wrong. If we make recommendations on their results, we could be doing harm or making the situation work. Drop kits are the gold standard.
I would get some liquid chlorine into that pool as #1 priority. Add 5ppm PER DAY in liquid chlorine. Use Pool Math to help you calculate 5ppm Link-->
PoolMath
IF your CYA results are to be believed (I don't until YOU test), you likely will want to replace 50% of your pool water. It is very difficult and expensive to keep enough FC in the pool with CYA of 100 to keep the pool sanitized. See this...Link-->
FC/CYA Levels
The only way to reduce CYA is to replace water. While you are adding 5ppm per day FC, and reading up pool school, you might read about a no drain water exchange in this article:
www.troublefreepool.com