Print it with the front face down on the bed for best results, it's deliberately set up to not require supports if printed at that angle.

If you're printing it front-down, then there's really no reason not to print it at 0.3mm layer height (or even higher if you can) as you won't see any of the artefacts. I used PETG but I'm sure anything will be fine.

To adjust the angle you can modify the “Wedge” sketch, either eyeball the angle you want or switch the angle to a driven dimension and specify it.

There are some spots underneath intended for 8mm feet pads, I used 3M SJ5302A Bumpons and they work nicely.