First off, welcome to the forum!

1. CYA is either added directly or adding in a form of stabilized chlorine. What type (ingredients) of chlorine have you put in so far? How long has your pool been opened? It takes awhile for the cya to start showing up in your test.

2. You only need to shock when you have green or cloudy water or if you get a CC reading when you test.

3. A skimmer net. I'm not sure why they tell you not to filter while people are in the pool.

Don't open anything yet that you haven't thus far until you test with your drops-based kit and post your numbers here. Let someone take a look at your numbers and advise you. You may be able to take back some of the unnecessary stuff. Also, tell us what type of shock the gave you (ingredient).