So, i agree that going to a cybersecurity boot camp to meet women is a bad idea. I know women who have gone to IT boot camps, and they were looking for jobs, not to socialize. And cruising there is going to feel creepy.
But i think dance is a great idea. There’s often a shortage of men, and the straight women like to dance with men. I am involved in “challenge square dancing”, which gets very technical, by the way. (Also, like IT, the sex ratio leans towards men as you get into the technical stuff, but it’s probably still 40% women.) And knitting is a good idea, too. My son has gotten into very technical knitting, and he’s attracted a certain number of female friends who appreciate that he’s really good at knitting. Of course, most of his knitting friends are already partnered and not looking for romance. But since he’s looking for friendship, not a partner, that’s fine. Anyway, the odds are pretty decent for a straight guy in that venue. Makerspace is also a good choice. I have no idea what the sex ratio is, but people work together and chat and share space on a regular basis. And everyone there is pretty technical. Fwiw, my local friends who help run their makerspace are women.