I'm Just 18 and I'm Losing my Hair. Advise Me with Something Good I Can Do to my Hair.

If you are losing hair and want treatment options you should schedule a consultation with a doctor.

First and foremost I would see a hair treatment specialist or a doctor that treats hair loss.  In general there are at least 5 basic treatments in different combinations used to treat hair loss and they are:
1) Nutritional support 
Supplementing the body with minerals and vitamins that support hair growth in conjunction with shampoos/conditioners and sprays that help reduce hair damage.
2) Low intensity laser therapy that helps improve the blood supply to the hair follicles and improves metabolism in the telogen phase(resting phase) and the catagen phase( shedding phase) which helps in the production of hair in the anlagen phase(growth phase)
3) using topical medications like minoxidil and finasteride 
4) PRP or Platelet Rich  Plasma which is derived from ones on blood. Blood is removed from the patient,  spun in a special centrifuge, platelets are  separated from other blood components and are injected into the scalp. By doing so once the platelets are injected they release growth factors that improve blood circulation to the hair follicles, revitalize and repair damaged tissue. 
5) Hair transplantation is the final solution for patients that have gone completely or partially bald.
There other emerging treatment modalities that can help people with hair loss, but the most basic ones are the ones I've enumerated above.

Hair loss can be very concerning for many patients, particularly when it occurs at a young age. At 18, a visit to a physician who is knowledgeable about hair loss would be the best starting point. This may be a hair restoration surgeon, facial plastic surgeon, or dermatologist. Even some primary doctors are knowledgeable about hair loss. A workup and evaluation for any medical issues that might be causing hair loss would be important. A family history of hair loss would also be very important to obtain.
If all of these things point to androgenetic alopecia (male pattern hair loss) as the cause, then treatments aimed at slowing or stopping the hair loss process would be recommended. These might include minoxidil, finasteride, PRP injections, or other topical therapies. A hair transplant may be an option at some point, but not until the early 20's at the very earliest.
All the best,