Very nice, I just started pushing buttons until my sand started to blow around then backed off a notch or 2. Those directions are something else!
Saw you were doing some research on Hannah checkers, they are worth the investment in the long run if your planning to do a coral heavy tank. BRS has some great videos on youtube for testing, I believe Thomas there has a favorites pack that I mainly use. Always check from Hannah directly if you decide to buy, 10% off first purchase and free shipping! Salifert makes some cheap easy to read test kits (Amazon), you want to get close but you don't need perfect (Hannah wont do this either). You could spend that cash somewhere else for now!
Depending on your salt brand and frequency of water changes, your system should be pretty close with Mag and Cal since this is in your salt mix. First checkers I would get would be Alkalinity, Nitrate, and Phosphate get a test or 2 done to see where you are. Biggest advise I can give you once you start testing is don't chase numbers!!! You will end up down a very deep rabbit hole chasing your tail and don't be afraid to fail, things happen and coral dies lol sometimes for no reason at all other than eyeballing them too hard!
Getting a cheap zoa, mushroom, or GSP and see what happens!! A duncan (should be cheap) would be a great started, grow very fast and have a very visual feeding response. Doesn't have to be your dream coral, think of it as a tester that will give you the confidence that you can do it!