steps to getting pool chemistry right

[FormerBromineUser]

Forgot to add targets:
CYA: 40-50 depending on how much sun you get
FC: 5-6 corresponds to above
TA 50 (alk)

[Anonymous [GDPR] European in the UK]

The TA will change as you raise the pH so wait, The pH will also raise as you add more chlorine so wait also if the pH is stable don't worry about the TA at all with a vinyl liner. I run my pool with a TA of around 30ppm as the pH is very stable at that level.
What is your calcium hardness?
So get your chlorine up to shock level to oxidize out the CC, which should be 0 to 0.5ppm