Light weight fabric tends to slip and pull and pucker. However, if you turn the dial down and the back feed dogs are pulling faster than the front feed dogs that will help to keep your fabric taut as it moves underneath the needle and will prevent any unwanted puckers.
*Is there anything else I should know?
Yes. But this is enough information to get you started. And just remember: You will need a little practice. Everyone does. But with that practice will come an understanding of how the fabric is moved through your machine and then you will be able to master any type of material you want to work with and have your project turn out fabulous! You can do it!
Hopefully that was informative and not to painful!
Just understanding what differential feed is and how to control it has already made a huge difference in the quality of my serged garments. (And has lessened my anxiety about serging…everything in sight….)