Forcetwelve, consider yourself hooked, and welcome.
As mentioned, a windsurfer with the right board volume can putter along in just about any wind while any kite has a minimum windspeed.
There are many variables that influence kite size vs windspeed, including kite make and model, rider weight and board type/size.
My minimum kiting wind speed is now around 10 knots (Sector 60 board, Lithium 12 kite) while the maximum wind speed I have kited is 40 knots gusting to 45 (twin tip board, Crossbow 7 kite fully depowered). I don't recommend kiting above 40 knots.
Here is some more info on kite sizes:
kitesurfing-handbook.peterskiteboarding.com/progression/choosing-the-right-kite-sizeEnjoy your kiting journey.
Here's a windy day at Inverloch