Do we have any tiling experience? or what was the other 'building' experience?
Have you any experience doing any other trades? joinery/elecy/plumbing etc?
How come its tiling you want to do?
If its definately tiling, I'd break the plan up into smaller plans, do the courses etc, then assess and decide what and how to then proceed.
As for the van, a little run-around van, for £2-3k will be good enough to start I'd think
Good luck and all that,
but if it were me, and I had the cash to invest, I'd be inclined to venture down a different route,
... but I want a burger van me!