When should I ask her out?

Okay so I'm a lesbian, and I know this is going to sound super bad but I've been talking to this girl on tinder (we are both there to find other lesbians TO DATE not to hook up with).

Anyway we've been talking for about 5 days now and I really like her, like she sounds super interesting and is very easy to talk to.

I was wondering, I wanted to ask to meet up with her, but obvs somewhere public incase she is a murderer. But how do I ask with out sounding creepy? And I thought movies and dinner would be okay for a first date because it's somewhere with other people but someone said that was really lame so does anyone have any ideas?

Thank you!