I have jaw pain in the left side of my face, minor congestion (normal for me), and feeling of a lump in the left side of my neck. could this be sinus?

Not a site for sinus: If the sinus is infected, then the lymph nodes could be involved, which do swell. With jaw pain and the lump, it is probably a muscle . You need to seek care and have the area palpated to rule out anything major.

Sinus: The maxillary sinus is located near your nose. If the pain is coming from there, then it might be a sinus infection. You could be coming down with a cold or have a bad tooth. A rotten tooth in the lower jaw can cause an infection that is draining into a space in the floor of the mouth. If you feel it is the latter, definitely go get checked!