You haven't said whether you'll be producing images for projection, so I'll assume you won't and you can ignore the last paragraph. When I was using negative films, if I wanted to travel light I took a 21mm and a 90mm macro lens and nothing else. They covered the bases that interested me - from which you'll gather that motor sports and birds didn't enter my field of view; which is another way of saying that what's useful for one person (because of they way they see the world - the perspective) and their choice of subjects won't apply across the board to everyone for all subjects. If I took a third lens, it would have been the 50mm f/1.4 simply because of the speed if needed. The old advice (= given in the 1960s) was to choose your lens on a doubling/halving of focal length - so assuming the standard 50mm, you'd add a 25mm (or thereabouts) as a wide angle, and then 100mm/200mm etc. as longer. That said, the normal trinity was 35mm/50mm/135mm. 35mm wasn't a focal length I found useful, but photojournalists did. Horses for courses applies.
It's been many years since I was a serious user of 35mm, and in those days I used either black and white film or Kodachrome. Never colour print film. The difference between slide and print film is that slide film is used (by me, anyway) to give a projected image. And a slide show where every image is a different size because of the different amounts of masking isn't fun to experience. Hence, with slide film, you either cropped carefully in camera by changing position (sometimes with a deletrerious effect because changing position changes perspective), were very lucky with the exact focal length you had with you, or you used a zoom. I used a zoom. With negatives, you can crop to produce the print, and, within reason, no one will notice.