I got hired 8/1/19 I went to my orientation but couldn't stay because I forgot my birth certificate on the table rushing out and I can't get in touch with the manager what do I do now

I would go there in person & ask for the manager.

Going to see if the hiring manager is on cuz that's what you're looking for their shift managers in hiring managers

I would just go in the McDonald's you was in and ask for help.