I'm 19 and I have these horrible bags under my eyes. I'm not sure if it is a sign of festoon. How can I get rid of it?

Please post some photos so we can help you. Without photos there is no way to give you an opinion on what can be done/

You should seek out a consultation with an experienced oculo-facial plastic surgeon, if possible.  Festoons are "cheek bag" that are present below the bony orbital socket and are a result of a potential space between skin and muscle which can get fluid trapped in it and look "puffy".  Bags under the eyes are usually the result of fat pockets that are normally under the eye starting to protrude.  In young people this is most likely due to volume loss in the mid face and is often best treated with filler, rather than removal of the "eye bags" since having fat behind the lower eyelid is normal (it's just the bulging appearance that causes the bag).  Find a board certified injection specialist who is knowledgable both in performing blepharoplasty (eyelid surgery) as well as filler so you can review your options.  Most people your age, in my experience, have a very natural and long lasting result with non surgical, filler treatment for this issue but without photos, there is no way I can guide you.Best of luck!