Hi awkward customer
That is an MBS Pro90 kiteboard. It is the first board MBS has designed specifically for land kiting (their boards are usually designed for downhill riding).
Funny you got it for so cheap, it's a $600 board.
I'm part of the MBS Oz team and use the same board myself. It's light (bamboo deck) and agile with great pop. It's smaller than other boards so it's ideal for rotations.
Make sure you use it on beaches with very hard sand and use proper shoes always.
The key is to use a lot of front foot pressure, if you use your normal kite stance you will immediately go too far upwind and slow down to a stop. You control this board the exact same way you control a snowboard, it's all about the front foot. Also avoid leaning too far back as you would on a twin tip.
Use a small kite to begin with, you can have a lot of fun and go quite fast in winds as low as 10 knots.
Start with slow runs with the kite close to 12 so you can easily control your speed and stop by bringing your kite to 12 or to the opposite side of the window. When you get better you'll learn to control your speed and stop by directing the board hard upwind and sliding
Enjoy!
Christian