It is always recommended you have an experienced mechanic assemble and tune your new bike.
There is that hard edge folding bike manufacturers live on----Most bike shops have no interest in folders----Most bikes should be assembled by experienced mechanics. There are always little things that need to be touched up when a bike comes out of the box. There are huge sections of the US and world that do not have shops stocking folding bikes.
Bike Friday and Dahon are both trying to sell through bike shops but not a lot of shops are willing to carry them.