NEWBIE Framing Issues

Taunt but not tight. You want the garment smooth and taunt with not stretching.
There are YouTube videos on hooping. Just do a search for embroidery hooping.
The principals for hooping are the same for home and commercial machines.
And, welcome to the forums.

You are really hooping the stabilizer. Be sure that is well connected with the hoop. After a couple of stitches, the garment is pretty much just along for the ride. Your design should include appropriate under-stitching to connect the fabric to the stabilizer... that's the part that actually moves the garment. In fact, the garment doesn't even have to be completely hooped... you can run right to the edge if needed.

You don't want to give the garment much slack to get moved around by the presser foot or to get pulled by the stitches, but if the fabric is too tight it will pucker.