Re: is this thyroid cancer?
You can't diagnose thyroid cancer from an ultrasound or blood work. Sounds like you have a "multinodular goiter" a lumpy bumpy thyroid, usually from thyroid disease. It's really common, and not going to hurt you. You can try thyroid medication to see if it helps with this.
They can needle biopsy those in the 1cm (10 mm) range, and try to see what cells are in there. It will only get a sample of these cells, so it's just another step in evaluating what's going on.
If the needle biopsy is benign (which 85-95% are benign) they will probably watch them over time for changes. If it's inconclusive, or suspicious, they may have to remove for a real pathology, because it's the only way to be sure.
Multiple nodules, one are often more likely to be benign than a solitary one.
The fna isn't a big deal, just feels like pressure for a minute or so. Let us know how it goes.