and if you meant swim in it for the first time of the season, I always like to shock it once before I get in, because who knows what built up in their over the winter, or whatever state it was before you filled it. Might just be paranoia, but gives me peace of mind.
Get it full, get it circulating, check for leaks. The, if you know how to use poolmath, add 3 ppm FC. Then fumble with the CYA and the sock. By then the water has probably mixed enough to test pH and TA. Adjust pH if needed. Give things fifteen minutes. That's about the time you need to get the kids slathered up with sunscreen and changed. Throw them in. Less than an hour from "Shut the water off, please," to "Stop that or I'll make you get out."
You'll probably need to wait a few days until it gets warm enough to suit you.