I went the other way, and started shooting stereo photos a couple years ago. So a 36 roll gets 18 stereo sets. I quickly learned I need to ask the developer not to cut the negatives, because they camera rolls the film at an odd length between shots. Unfortunately, they cut a few frames in half... but luckily, I had the other angle, so now those ones are just nice, stand-alone pictures.
I then process the negative at home, with a slide scanner, a touch of colour adjustments and then pairing and aligning the correct images. Quite a bit of work, but it's also simple and becomes something of a routine after 2 or 3.
I use a trusty use a Stereo Realist, it's a rangefinder camera, and surprisingly quick to use once you get used to it. It's also reasonably small, so when I first got it, I took it with me for many shoots for some lovely stereo behind the scenes snaps. Happy to share a couple, but you might need some equipment to get the stereo effect. either a stereo viewer, (those VR headsets you can put your phone in work very well) or try the ol' cross your eyes and stare through the frame - which can get a little exhausting after a while.
EDIT: It's a shame stereo-photography never really took off with digital. There's only a handful of models that do it well enough to be worth the time, and they're few and far between on the second hand market. Recently I've been looking at beam splitters, but even those are hard to come by. They are available for phones, but I don't think there's enough usable resolution (on mine at least) to have a good image once you've cut it in half.