No problem your 8 m2 will be perfect for learning, as you will need 16 mph wind for the first times out and an 8 m2 is quite slow because of its size.
You ride waves so are used to "normal" kitesizes 6 to 8 m2 max and not these huge ass balloons some use
One thing - use one strap or hook when learning, you will learn WAY faster this way, and then you can take it off
Many of my "waveboard" friends have learned on their 6 and 7 and 8 m2 kites.
When you have learned, you can use your 6 m2 in 18 mph, and your 8 down to 12-13 mph.
For below 12 mph you need a single strut or strutless 12 m2 kite, if you are average weight, and you will eventually be able to go down to 8 mph winds.
Board - not too small for starters.
Foil - not too small a wing for starters.
Peter