I have multiple little swollen lumps (i think lymph nodes, but sure) on the back side of my neck. the lumps are pea-sized. these little lumps are only on the right side. the lumps do not hurt or move. i have had these for 8 days. what are these?

The lymph nodes, if you are correct, are movable if benign, i.e. reactive lymph nodes. You should observe them for now, see your doctor if they get bigger.

At 19 years, instead of speculating, it will serve One better to see the PCP, in person or virtually to get a clinical feeling of the nodules and decide if further Workup/Investigation is necessary.