Hello, I am a 30 years old female. My left foot has been swollen for a year now. I usually feel a pain on the last toe nail on my left leg which hurts. What should I do?

Not sure. If only one foot is swollen, this usually means the cause is something local, not that you're retaining fluid (which would cause both feet to swell). I'm not sure if the pain and swelling you're getting in your leg is related to your little toe. It would be impossible to tell without seeing you. I recommend you start with your pcp, who can refer you to a specialist.
See a doctor. it is not normal to have a painful swollen foot. start with your PCP who can then refer you on to a specialist.
I would try and . Figure out why your foot was swollen and if there is some way that could be treated. Keep in mind, you need to find shoes that are a proper size end fit.