Fellas I need your help,

So I was in a group of 2 with no wingman and ended up getting both girls' numbers this Sunday (Mar 3rd). One of them was actually someone I knew, but never really paid attention to and I'll call her "my acquaintance" to distinguish them. To get the hotter ones number I told her that next Sunday (Mar. 10) I was going to the opening of a bar/restaurant owned by my cousin. She asked a few buy-in questions and then I asked her for her number and to invite her. I didn't tell my acquaintance about the event.

My question is the following:

1) Should I text the hotter one to try and go out before the event I told her about?

2) If not, when and how should I text her about going on Sunday? I thought about inviting both in a group text, because she would be more likely to go if a friend went.

Any help is appreciated.