The tension on your long arm is quite different than your domestic sewing machine.
Remember left turn for loosie and right turn for tightening.
On my machine I can turn it left a couple of turns before it will loosen and then right again lots to get the tension to feel ok on the top. I found I just had to get comfortable with it, and it took awhile, and a lot of patience. Also found that I didn't have my needle into its slot exactly north and south (or east and west), so had to be certain it was correct. If you find lots of loops on the bottom, it will be your top tension that is the problem. I had to figure out how far I could stitch before my bobbin would run out, if I doing lots of stitching, dense quilting, sometimes I could only do
a couple of rows, then the machine would go all funny and found out the bobbin had run its course. Jut saying its' all a learning curve.