Do lots of people get laryngitis, or is it unusual?

Common. Laryngitis is an inflammation of the lining of the voicebox (the larynx) and occurs as a residual effect of colds and other upper respiratory infections (which are common) but can also occur from overuse (lengthy singing or yelling loudly like at a sports game) and rarely from growths on the larynx. Your otolaryngologist can evaluate this and give you the best remedy.
Yes. Laryngitis occurs quite commonly. It stems from inflammation of the laryngeal structures and in most cases it is viral. Patients should maintain good hydration, avoid voice use if possible, and take anti-inflammatory meds (ibuprofen). If it persist more than several days, a course of oral steroid can help. But, any case that lasts more than a week, should be evaluated by an md.