When someone texts me: Me: Omg someone texted me Me: What do

When someone texts me:
Me: Omg someone texted me
Me: What do I do? this is so exciting
Me: Opens the message that says "hey"
Me: Hmm I don't want to respond right a way because they'd think I was looking at my phone waiting for someone to text me but I don't want to wait to long or they think I'm ignoring them
Me: Waits a minute trying to stay calm
Me: Oh I'll just text them now
Me: What do I say?
Me: I could say "Hi", "Hello", "Hey", "Howdy"
Me: So many options
Me: Sends text saying "Hey"
Me one second later: Why haven't they responded?