Hello and welcome!
There is such a wide variety of faux furs out there, I don't think there is a single answer. I haven't worked with them in a number of years, but once when I still did garment construction, I made a (lined) coat out of thick blue polar bear... I typically use a 14 needle to quilt with, but I think I went up to 16 or 18 upholstery needle on that. I believe I also got a heavier non-standard thread. Keep in mind your stitch length should start large too.
In other furs or fabrics like minkee it hasn't been that big a deal. Again, I would start with a 14 needle and maybe about 8?? stitches to the inch and see how everything reacts. If it is something more like minkee, a 12 needle and maybe 10 stitches to the inch would be the place to start.
After you are done with the seams, you take something like a toothpick and on the visible side pull the hairs out of the seam as much as you can if you want to hide the seams. Don't have to bother if you want the look of the seams. Once you get the top all nice and full with a thick fur you can shave the seam side down -- it was necessary for my project but makes a ton and a half of fluff!