$20 an hour? Dude. you suck. They deserve more respect than that
bro.
If I were you, I'd work part-time at Macs or something, earn at
least a decent sum of money, like maybe $200~$300, give a better
offer like paying for the hotel accommodation, dinner, and give her
around $100 for that hour. She can choose to stay on after that or
not.
And anyway, it's not about your looks, it's how you portray
yourself dude.
If you think this is something you want to try it, then go work
for a month, save up the money, then try it properly.
All the best to you.