I am 20 years old still don't have full beard,just a goatee? What shall I do?

What CAN you do? What should you do? Shave... so nobody knows. There is NOTHING you can do. Unless you want to glue a piece of fur to your face... but don't do that... it looks like hell.

Maybe when you get older you will have more... but maybe you never will... thats genetic and you get what you get.

Either wear a goatee or shave, there is nothing you can do about it.