Yes, most first dates usually last about an hour or two.
In my experience (and reading posts on here also), the length of a first date has no correlation as to whether or not it leads to additional dates.
I’ve had my fair share of 5+ hour first dates that end up with a rejection text shortly there after. Shorter dates of about a couple hours I think is a good sweet spot because it gives a good amount of time to get to know one another, and also leave something to be desired if everything goes well.
A long first date isn’t necessarily better because often times people fall into the “caught up in the moment” trap where you end up getting the sense that the other person was into you, when they probably just felt good to spend time with someone and liking the attention and the feeling it brings, but after realizes they weren’t really into you. And then when the rejection comes you feel like you got blindsided.