Dating rules are always really just one step away from game play— hell, sometimes they are straight up game play. That's never a good thing.
It's completely normal to feel nervous about a first date, most people do. But instead of feeding into that anxiety by overthinking it and obsessing, try to take a step back.
Sure, there are times when it's really obvious that you hit it off— or really obvious that you didn't— but things aren't always so clear.