I used to wear glasses and when it comes to glasses they're, for the most part, genderless, the difference in section is more for size difference. Women tend to have narrower faces so the sizes are more suited to them. I personally have a tiny head and some of the women's glasses were better for me in size but they were more unisex than women's. The issue you might find shopping in the guy's section is that finding sizes will be harder. In the end I ended up getting teenage frames and teenage frames aren't split into genders, so that kinda speaks volumes because teenagers are male and female too, so it's more a size thing. Obviously there will be some styles that are more feminine but in general glasses are glasses and advice about what style suits different folks is based on shape of your face, not gender. I wouldn't even say there's a masculine style of glasses, I've seen guys with round and I've seen them with rectangular. Sometimes rectangular just doesn't suit people's faces and they look ridiculous, and vice versa. Whatever works for a guy, works for that guy. Glasses are glasses, I wouldn't look for masculinity in them, I'd just look for what works.
I wouldn't worry about it too much. If there's something you like in the guy's section then check them out. I find that if you go somewhere good and know the size that fits you (the 3 numbers on the inside of one of the legs), they'll find you a good few options that would work based on size and guy ones may well pop up in there (or teenage if you have a teeny head like me lol). The length of the legs (3rd number) can be altered to a degree to suit, but the first two numbers are more fixed with very little leeway (taken in, not so much expanded).
BTW, I totally get if you just don't want to have anything even remotely considered feminine (I relate) but maybe asking them to pick them out based on size and just not tell you what section they came from, and then you never know if they were supposed to be for women!
