Greeting...what are the things (to do or to eat) that promote hair growth? Thanks

Depends on reason. hair loss can be due to a lot of medical problems. You need to see your physician to have this checked out. Some people have found success with the use of a supplemental called biotin.
No foods. Biotin will do nothing. No foods or diets promote hair growth. Do you have a problem? If you are losing hair and wish to keep your hair, see a dermatologist. Meanwhile you can begin to use minoxidil twice a day. The generic 2% is least expensive---$4 a month---and just about as effective if used religiously for many years.