Liz is a simple woman. A perfect date for her would just be stimulating conversation (where her partner viewed her as a an equal), possibly a dinner, and the chance to go look at the stars. I don’t feel like she’d be into anything too ‘exciting’ nor would she want to sleep with the person if it was a first date, she’d just want to really get to know them and feel comfortable in their company. She’s not too classically romantic so she probably wouldn’t want chocolates or flowers or anything like that but rather, for her partner to share a hipflask with her whilst they looked at the sky together and talked about their lives.