I haven't had my period for 6 years now iam 20 years old will I be able to have kids later in life?

Need more info. If you haven't had a period for six years, it's possible a - you have no eggs left. B - you have good eggs, but you're not stimulating them with the right hormonal sequence or c - there is a blockage preventing the blood from coming out (although you would expect pain with this last one). With b and c, it's more likely you can have kids. With a, no, unless you use an egg donor.
Possibly. Absence of menses for 6 years is a long time. It possibly could be due to premature menopause, and this is something that should be checked with your gynecologist. Other reasons could include abnormality of the pituitary hormones leading to a lack of ovulation and a normal menstrual cycle. Again something that you should check out with your gynecologist.
Possibly. First and important step is to seek evaluation with your gyn for your lack of periods or amenorrhea. Depending on the etiology for the amenorrhea will dictate your short-term or immediate treatment as well as determine your prognosis for fertility long-term.