I think you meant “powers of two” not “square numbers” near the end there

Yes, the article explains what Control Net is for those of us who haven’t heard of it before. And the article says that Control Net was (apparently) initially meant to be used for qr codes.

Can you recommend a place to start brushing up on that?

Since you guys are new I would like to direct your attention to the following excellent resources:

• https://2e.aonprd.com/ - Has all the rules for Pathfinder 2e
• https://pathbuilder2e.com/ - Character creator for Pathfinder 2e. Free, but requires paying a small one-time amount to get access to Free Archetypes, Pets and Cloud Storage
• https://wanderersguide.app/ - Character creator for Pathfinder 2e. Free, but a Patreon subscription is required for more than 6 characters (I might be wrong on this part)
• https://www.youtube.com/@HowItsPlayed - Excellent YouTube channel with videos about most rules
• https://imgur.com/LjllYua - Overview of the classes and their general strengths
• https://foundryvtt.com/ - Virtual tabletop with excellent pf2e integration. One time purchase for GM + ongoing hosting cost

As someone who likes to build their characters ahead of their current level I too prefer Pathbuilder, though for new players Wanderers Guide might be a bit more hand-holdy.

I believe both of them can output a pdf of the character sheet if you prefer to play without tablets/phones, and both can handle at-table play, though for Pathbuilder specifically I would recommend a tablet/laptop over a phone, because the website is a bit more friendly for at-table play.

I would recommend starting over at Lvl 1, because characters get quite a lot of options over the levels, so starting with only the Lvl 1 options can simplify things quite a bit. Though I know that some people have done a “You are depowered for some reason” or “You are dreaming of a time when you weren’t as strong” period to somewhat quickly level up from one to where you were. If you do this, be aware that characters will end up differently than your 5e versions, and that pf2e expected certain magical items at certain levels, such as Potency and Striking runes for martials and Wands and Staves for Casters.