I've been on the Venturi 190 for about 4 months now. here are a couple of pointers:
- set your footstraps very very tight. you want to get your feet as far out on the rail as possible, so that you are putting pressure "sideways" in to the fins, not down on to the rail like a twintip. You end up with really just your toes and the very front of your foot in the straps, unlike with other boards.
- play around with front-to-back footstrap positions for both feet. it can make a big difference.
- if you want to maximize the board, upgrade the fin set. It will make a BIG difference. both faster and easier to ride correctly.
go slow at first.
I'd agree with most of the comments above. If you've never ridden a race board, be careful not to kick the fins under water while you are floating next to the board.
if you are not used to a race board, chances are that the first few times you go for your powerdive you will push down on the windward rail as you would with a TT or surfboard. You'll learn quickly that this doesn't work. I'd agree with the comment for turning downwind a touch and more frontfoot pressure (eventually you don't need to turn downwind when you're comfortable).
If/when you do over pressure the windward rail, the board might feel like it want to buck you off.
Honestly if you get to this point, don't fight it or try to muscle the board up. It's too late. you'll just ding your board or yourself. Just jump clear of the board (probably flying over the front and downwind) and try again.
I would say though that as far as race boards go, the venturi 190 is a very easy starting point. Specifically, the larger venturi is the easiest.
good luck.