Tap to dial phone # in Notes on iPhone?

On earlier iOS versions, it's a bit different.

Double tap on the number to select it, then tap on the right most edge of the ribbon, past the right arrow. This should make the ribbon disappear and turn the number yellow and underlined. Tap once on it and you should get the option to call it.

Convoluted, yes, I know.

Screenshots from an iPhone 7 running iOS 15.7.

Yes. Double tap the number to select it, then tap on the right arrow in the option ribbon that appears until you see the Call option, then tap on Call to initiate a call to the number.