Where do you meet guys to date?

I went through a breakup recently and am now looking to get back out there. The problem is I can't seem to find anyone who wants to actually date me. I feel like I'm reasonably attractive, not ugly but wouldn't say I'm hot. Anyway, I guess my question is, where do you meet people? I'm a little introverted so I don't really go out a lot and I never know when people are flirting with me haha.