is it possible to do this trick without jumping off your board first ? do kinda just jump and flip ?

Just learn how to flip Whit a skate Whit a leg and try to land on. Just don't give up. 😀

Are there different ways to do this trick?

I've posted a video of my old school kickflip

So... like the old school Varial without the exaggerated leg split motion so rather webasically hook frnt ball/ front angling under? Right?