Sneezing, itchy eyes. I wake up with a sore throat, I have swollen lymph nodes in neck for awhile. What could be the cause? Allergies

Monitoring Centers. Lymphatic system absorbs/carries things too big to go into the arteries/veins like bacteria eaten by white cells and digested food. Lymph nodes "taste" the lymph for anything bad like bacteria/viruses/cancers, etc. When it detects a problem, it alerts the immune system and your body reacts. They enlarge in response to the inflammation they create when they react. They shrink when all is well.
Multiple. Allergies, upper respiratory infection, and cancer would be considerations. While cancer would be most worrisome if you were older and smoked, there are some blood cancers that can cause this. It is very rare. If the nodes don't go away in a week or so, see your doctor.
Allergies likely. Sounds like fairly typical allergy symptoms. A cold(uri) and allergy can be very similar, but a cold lasts 5-7 days and you feel more sick. Allergies last much longer, like for an entire season, or year round. You don't feel quite as ill with allergies.