Well, yes. if you're looking for a coventional flattering portrait then a 50 to 90mm lens is the usual choice, but sometimes you can work WITH the distortion to give you a more dramatic effect. This was shot 32 years ago with a 19mm f/3.5 Canon lens.
http://photos1.blogger.com/blogger/6344/1997/1600/Blog 7 adj.jpg My daughter Elena is now 37.
Unless you're shooting some specific subject lens choice is mainly based on how YOU see the world. Some people like to stand back, observe, and might choose a longer focal length. Others like the feeling of intimacy, of "being there", that you can onle get with a wide angle. It can almost make you feel like you're IN the picture.
Look at a scene, any scene at all, and compose the picture in your mind. What's in it, what's not, the best place to shoot from, all that stuff. It might be perfect for a 28, maybe not. Most of us instinctively gravitate to one or two leses for most all our shooting. The rest may be fun to have but rarely used.
Use that 28 for awhile, try others, make use of the frame selector lever to check out the coverage of the others. For now I'd forget about a 50 and add a 90 to your kit. That'll cover you in most all situations.