First conversation with a native speaker: Are my case endings correct?

I have my first 1-on-1 Romanian conversation scheduled for the weekend, and I’m sweating the Genitive and Dative cases. I know the rules when I write them down, but I’m terrified of misgendering nouns and getting the 'lui/ei' logic wrong in conversation. Any tips on surviving a live chat without sounding like I’m reciting a grammar textbook?