First, check your manuel to see if your problem is addressed. Check the diagram in the front explaining where everything is located on your machine. I just looked at a picture of your machine (looks nice) and there is a small knob on the left back top that appears to be the knob you are looking for to change the pressure foot tension. Make a sandwich just like the quilt you want to quilt and adjust the knob (check manuel for how to adjust...some turn and some pump up and down). Sew a little with each adjustment and check to see that the stitches aren't looping on back or front, etc. I hope this is helpful.
If you change it too much, the feet on the bottom won't move the fabric through.