Most probably you have infection in your throat (usually pharyngitis
, rarely tonsillitis ). Lump in neck is due to enlarged lymph node
that is secondarily affected from throat.
However it is important to examine you to find out, what exactly is the problem with you.
Mostly a course of antibiotic with an anti-inflammatory would suffice.
Most likely it is not related to thyroid or parathyroid
You please consult an ENT specialist
and he will suggest if any test is required. No need to do any test before you see him.
Wish you good health.