Met a girl last Friday at a RaceTrac of all things, went with the direct method basically got her number in about 5 minutes, then texted her during that evening to try and build some attraction.
Had a date with the girl this past Tuesday, basically just chilled at a bar for like 4 hours, pretty much lost track of time. Asked her what she had going on this weekend, she told me she had no plans, I k-closed and left it at that.
On my drive home get this:
"Hey, Honestly had a good time and I'm attracted you. Which isn't very often, I'm pretty picky. Can't wait to see you this weekend."

Text her earlier today letting her know Im going to a concert tonight with friends and to come along.
Her Response:
"I have plans all weekend, but I may be available Sunday evening"
Me:
"I'm actually busy Sunday evening"
Her:
"Next week maybe"


WTF did I miss?

You did nothing wrong IMO. She just made plans before you texted her. Sounds like she's into you, so if you keep your cool and don't start acting needy (youre not as of right now), you should be fine.

Should I wait for her to contact me or should I contact her after an extended period of time?

If it was me, I would give it a few days until you contact her. Like I said, don't be needy or anything, but I definitely think you should contact her next week, ideally to set up something. I think the only way you could really screw up is if you did something to DLV, come off as needy, or straight up don't do anything so that she others about you. She seems interested. You got this.

Hey man, I don't think you need much help, you just need to set up a time to meet and do it. Personally I would throw one or two cocky/funny texts her way first so she feels the same attraction again, and then set up a meeting time.

Heres a link to a bunch of pua text openers. I don't use routines, but some good text openers have helped me lead into a good text conversation. I actually used one of these the other day to get a girl that wasn't talking to me to wanting to hang out, so they're pretty good if you follow up well.

list-of-text-messages-game-vt21175.html?highlight=

Hope this helps, good luck man