Let it circulate a while to mix well. While that's happening, you can mess around with the CYA granules and the sock and get that going. You know there won't be any CYA in the tap water, so you can safely enter zero in the now column of poolmath. Target 70, since you'll be switching to the SWG soon enough.
Then you can add -- no need to wait -- enough bleach to get to 3 FC. Whatever FC was in the tap water will be gone in an hour with no CYA, so you can assume zero there too.
Then test pH, TA, CH. If CH is high, there isn't much you can do about it. Draining and refilling won't help since it'll just be more of the same. But knowing what it is will help you target pH and TA ranges in the future. Low CH is no problem with a vinyl pool.
If you're uncertain what to do about the pH and TA, post the results and someone will be along to advise.
Once the pH is in range, it's safe to get in.
Maintain the FC daily for the CYA level. If it looks like half the sock is undissolved, figure you have half the target, and use that value and the [FC/CYA][/FC/CYA]chart. Remember, it's a bleach pool at the moment, so use that value. As an aside, it won't be unexpected to find all the FC gone in a day. It doesn't mean anything's wrong, just that the CYA hasn't gotten to work yet. Don't panic.
Any time in there once the pool is swimmable and you're sure there's no leaks and the pump and filter are working, you can add the salt. It's fun to pour it in and let the kids play with it.
When the salt and the CYA are both dissolved for a full 24 hours, you can turn on the SWG to maintain the FC.
