Autistic

For context: i am autistic and i have trouble reading body language, context etc. I also take things literally a lot (e.g. an interviewer said “this is the make or break question - which football team do you support?” and i damn near had a nervous breakdown because he said it was make or break). I also have a “flat” personality unless the topic is something I’m crazy excited about like Minecraft or submarines. Anyway - i have done 3 interview rounds with a company and a technical exercise. Apparently i did really well in the interviews although i had no idea because as i said i cannot read signs, context, jokes etc. Now the hiring manager wants to take me for a coffee for an “informal chat” - what does this mean? What am i expected to do/say? Any tips? I have literally zero idea what to expect other than the recruiter told me to “lean in” when talking. I don’t know what that means. So please - what do i do? I get very confused with social norms and etiquette so please spell it out slowly for me.