Whether you need surgery or not, can only be told by the reports of FNAC, histopathology, preoperative USG characteristics and other clinical parameters that determine your risk of recurrence. Regarding complications, you may have to take
thyroid hormone replacement lifelong. Other complications that may occur with surgery include parathyroid removal or damage, damage to laryngeal nerves etc. You can get married but if you get post op radioiodine therapy for you thyroid cancer, you should not get
pregnant for atleast 6 months.