For those NOT having experience with surfboards nor windsurf waveboards, I always advocate to start out strapless.
It is a bit more difficult the very first days, but no biggie.
And when learning to jibe and tack, it is way easier without straps
This is IMO the only way to learn how a surfboard handles and should be ridden, as otherwise you wont learn anything about the most important things, namely weight distribution and how to use the edges
It will also help you get rid of your bad TT habits, as they are useless on a waveboard, and directly wrong, typically opposite
So start out without straps to learn how things work, and to get acquainted with the board
When you get the hang of this, you can move on to the next level, and start using straps - for much more hold and performance and speed and upwind and chop and aerials etc etc.
(or you can keep riding without straps, for those for some odd reason only believing in this...)
But start out without straps, so you dont just "hang on" to the straps and use bad technique inherited from twintips.
This way you will be able to utilize the waveboard to the max, when you start using straps later !
Finally, when you are "Fully Educated", you can also choose to ride both with or without straps, depending on board and conditions, or personal conviction.
And remember - going out in very small waves and a bit sideshore wind is the best for learning