Dating, idk what I'm doing.

I'm trying to date a bit cuz I feel like I'm getting to the age(27) where I need to start settling down. I'm not the best at showing how I feel when I'm on a date cuz I don't like being vulnerable. Problem is that it makes me hard to read for who I'm on a date with and they feel like I'm not interested when I am. Also, I have this thing where I feel more comfortable having sex with the guy first and then getting to know him. My friends say that I shouldn't have sex with a guy until we've been dating for a bit. So, any advice or thoughts?