Most thyroid nodules are benign. Most doctors will not recommend a biopsy for a thyroid nodule smaller than 1 cm, and some places they wait until it is above 1.5 cm. Since you have one thyroid nodule that is above 1 cm and is hypoechoic, which makes it more likely to be malignant compared to an isoechoic nodule (same texture as the rest of the thyroid). The chance of it being malignant is still low, and depending on your doctor, they may want to do a fine needle biopsy soon, or they may just want to monitor it at some interval (usually between every 6-18 months) by ultrasound. Most thyroid nodules are slow growing.
As for the lymph node - I'm not a medical professional and I don't want to give you bad advice. Lots of things can cause an enlarged lymph node, including a recent illness or infection, as well as more serious concerns. I do know that it is possible to have a neck full of swollen lymph nodes and none of them be cancerous (I had thyroid cancer, it had not spread past my thyroid, but since I also have Hashimoto's, an autoimmune disease against my thyroid, my neck was full of swollen lymph nodes, none of them were cancerous - they pulled out 14 lymph nodes total during my 2 surgeries and did pathology on them). Level 3 just describes the location of the lymph node - level 3 is "located between the hyoid superiorly and a horizontal plane defined by the inferior border of the cricoid cartilage."
My thoughts - the doctor may want to do a biopsy of the 1.2 cm nodule, or may recommend follow up ultrasounds to monitor it to see if it changes in size. Depending on what they think about the lymph node, they may follow-up with that as well (biopsy?). I'm not familiar with lymph nodes on ultrasounds - I had two ultrasounds before my first thyroid surgery and they didn't note any lymph nodes, but during the surgery there were massive amounts of swollen lymph nodes that had clearly been present during the ultrasounds (the immune attack against my thyroid was chronic, so lymph node swelling was also probably long term).
Good luck with your follow-up appointment with your doctor. I had so much anxiety when I was going through my whole thyroid diagnosis, waiting three weeks is really hard.