For most projects you should be able to use the regular all-purpose thread and I use this for 99% of the time. Usually 100% cotton thread is used for quilting, silk thread is used for delicate fabrics like silk, the shiny rayon thread is used for machine embroidery, and heavy duty thread is used for when you’re working with heavier fabrics. There are other specialty threads but as a beginner, you’re fine for sticking with all-purpose. Good luck! 🙂