I damaged my skin in sun beds at aged 21. Now my face skin is sagging. Can I get a facelift?

doubt you need a facelift if you are between 18-24. without photos or exam its tough to give a great opinion but at your age if you have damage from tanning beds (very possible) the best treatment would be aggressive skin care or perhaps a laser treatment. best to see a board certified plastic/facial plastic or dermatologist with laser experience

If you had skin
damage at a young age you should begin with
aggressive skin care, such as sunscreen andRetin-A  lifelong. One may consider a chemical
peel or laser at a later age. I would not recommend a facelift until you have showed significant skin laxity. One can also resume having
Fillers to help reshape your face

if you
have had volume loss in your face
as well.

Sun tanning and smoking are the two worst things you can do to age your face and skin, so it's not surprising you find that your face has changed so much.  However, if you are in your early 20s it is extremely unlikely you need a facelift.   A photo would be beneficial to allow us to give you a better recommendation