Hi there Afi, since you are having a burning sensation after urinating you should see a doctor as you may have a urinary tract infection (UTI), or a yeast infection. These are easily treated and many people, particularly people with vulvas have had to deal with one, the other, or both at times in their lives, however they cannot be left to "get better" on their own and will become an issue if left untreated. Also a person doesn't need to have had sex before to have either of them.
You can read more about them here:
UTIs:
I think I have a UTI: what should I do?
Yeast infections:
The why and how-not of yeast infections
Do you have a doctor you'd feel comfortable talking to about this?