sync presets from Windows Lightroom into Lightroom for iPad

What do you mean by "Windows Lightroom"? Are you referring to Lightroom Classic, or the Lightroom cloud-based desktop app?

If you mean the Lightroom desktop app, any presets added to that app should automatically sync via the cloud to the Lightroom app on the iPad.

If you mean Lightroom Classic, then presets do NOT sync to the cloud. However, presuming they're on your local system you could import them into the Lightroom desktop app, from where they should then sync via the cloud to your iPad.

That depends what "Windows Lightroom" is supposed to mean. Lightroom Classic does not sync presets, but Lightroom desktop does. To sync Lightroom Classic presets to the iPad, you will have to install Lightroom desktop as well on your computer, so you can import the Lightroom Classic presets into Lightroom desktop and let them sync from there.