There isn't a set formula for when one might use a wide angle vs a normal lens, vs a telephoto. It depends on the compostion you would like to make, and how much, or how little of the scene you want to show in the frame. Conversely it may also be helpful to think in terms of the image size you would like. Short focal length lenses (wide angles) make smaller images, longer FL lenses make bigger images.

In various contexts, there are also other considerations, for example, in studio work when photographing objects, it is helpful if the camera is not too close to the subject, so that you can move around easier to set things up. For this, a longer FL lens is useful so that you fill the frame with the subject from a larger distance.

For portraits, especially "head and shoulders" shots, short or normal FL lenses accentuate body parts closer to the camera, for example noses. The effect is certainly common enough in advertising and promotional photography, but a longer lens will avoid that and give a perspective that's closer to what your eyes capture.

It depends on what you like, if you find that you do a lot of cropping when you make prints, then you may find that a longer lens will let you do less cropping and let you use more of the film area. OTH and if you can never get enough of what you'd like to in the shot, then a wide may be the ticket.

Finally, don't be afraid to move around with your "normal" (or any) lens. Don't just stand in one place and switch lenses until you get what you want (unless you're at the edge of the grand canyon) .