I use black on black or very dark fabrics and white on everything else - bobbin thread and stabilizer.
Put your tension setting back to the factory setting, or setting recommended in the manual.
Thread the machine with the presser foot up.
Be sure the thread from the bobbin in coming off the bobbin in the correct direction and is going through all the guides.
A very dense design will need a heavier stabilizer than a design with less stitches.
A dense/heavy design will need cut away stabilizer and never tear away.
Test new designs before doing the project. Always test with the same fabric, stabilizer, bobbin thread, top thread and needle that you will use for the final stitching.
Remove needle, throat plate and bobbin case and clean this area often. The thinnest snip of thread or lint can cause a major headache. Never use canned air - just a soft brush or cotton swab and a gentle touch.
Change needle often.