Every lens from wide angle to telephoto has been used for portraits, however, because of the nature of the filming of the people it usually accepted to be back, out of their face, by a comfortable distance.
A 50mm lens will have you right in their face if shooting head shots. Head and shoulders you will be back a little more, but not too much and you both will smell what each had for lunch...
I always liked lenses from 85mm to 180mm with my 105mm and 135mm being my favs in most cases. My 85 f/1.8 when allowed to be used wide open has fantastic brokeh.
50mm 1.8 lenses are quite inexpensive, even new. The prices of the others will vary and if curious, looked up in your area.
Just remember, if you go with a 50, your going to up close and personal with many of your models, but it will work.
Bob - Tucson
