{online dating advice}

I joined a few online dating sites a couple weeks ago. I've mostly gotten messages from guys that I'm not interested in at all, but there have been 3 that I can see myself liking. I've been on 2 dates with one guy and he's really nice, smart, and seems like a genuinely good human being. Two cons about him for me are 1)he vapes and 2)he's a little shorter than me (I'm 5'8"). I really like this guy, but I feel like I'm just hung up on those two things. It has been almost 3 weeks since our last date (which went really well) and he has asked me out at least 3 other times. I like him, but I don't want to lead him on if I'm not sure if I can get past the vaping and the height thing. I don't know what to do. Also, there are 2 other guys that I've been corresponding with via text/messaging. One of them is really pushing meeting in person, but I don't know if I should do that while I'm going on dates with someone else. I'm late to the whole dating game and I don't know a damn thing about dating etiquette...like is it ok to go on dates with more than 1 guy if I haven't declared exclusivity with either of them. I need some advice, yall. Thanks in advance!!!