New pool Startup. What comes first?

[Beth222]

30 Ft Above Ground
Chlorine
1.5 HP pump
21,000 gallon
Vinyl

What do I add first to get new pool started.
Approximately how much of each
Chlorine
Baking soda
Stabilizer etc.

 

[YippeeSkippy]

I would start with 30ppm of CYA hung over the side in front of a return (not touching wall) in a sock on a broom stick or like, and then add as much liquid chlorine as gets you to 5ppm FC. Without having any idea what your pH or TA is, I can't advise, but that's all further down the list of what to do immediately after fill.
Can you provide them, please? No need for baking soda at this time...or ever. Needs more info.
Do you have PoolMath on your phone yet? That will guide you as to amounts to reach goal levels.

Maddie