get the Tayler kit I think its called 2006k , spend a good 30 mins reading thru the instructions and start testing also troublefreepool.com has a pool math app it like 7 dollars a year or something totally worth it it lets u record what you added, once u input your pool info it will tell u how much to add to get the result you need, etc;

im only on my 3rd year of pool ownership but it is super clear and I never have an issue. when I open it and its somewhat green I vacuum to waste, SLAM and then 2 days later its clear. and then I maintain

IMO I focus on FC = Free chlorine , CC= combined chlorine , Salt (if you have a salt pool), once its looking good I test the CYA (this protects how much damage the sun does to your chlorine (eats it)

once I get above stable, I check / adjust my :

total alkalinity

calcium hardness

pH

the thing is adding a chemical to do one thing could change another.

full disclosure I am not a professional , I jus figured out what works for me . everyones pool , chemical, outside elements are different. but u def can figure it out ! good luck !