For 35mm, the contact sheet conundrum is the best argument for bulk loading. I buy the negative holders that hold 7 strips of 4 negatives each, and load 28 exposures per roll.
For medium format, I've got 6x4.5 and 6x6 covered, but that 10th 6x7 negative remains a source of frustration.
As to how many I print - it really depends
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If I have a particular purpose in mind when I set out with the camera, I most likely will end up printing fewer from a roll, because the contact sheet will give me answers about how successful my various shots are.
If, however, the shots on a roll are just the results of photographing things that I come across and find interesting, there may be several sets of shots on a roll that I choose between, and several prints may result.
Some times, of course, I'll take a bunch of photos at an event or a gathering (e.g. a birthday party) and I'll print just about all of them (smaller prints usually). For this sort of work, an enlarging meter is very useful.
As you are relatively new at this, it probably benefits you to print more of them. That way you'll learn about those circumstances where the small size of contacts tends to obscure the strengths of some images, even if you have a good loupe (and I heartily recommend a good loupe). Also, there is no better way to improve your photography (composition, perspective, exposure, dealing with movement of camera or subject, film development) than to practice printing both good and problem negatives
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Matt