Teacher candidate first day suggestions

I'm beginning my first practicum in 3days and I'm a little nervous as I have been placed with grade 5s. I majored in ECE and the oldest grade I've gotten to work with are grade 2s but even with them I find that I come off too friendly and while they like me, I find it hard to get them to respect and listen to me. I've never really interacted with or planned lessons for grade 5s so Im not sure what to expect. What kind of introductory get-to-know-you activities can I do to go off on a good start? Any suggestions will be appreciated.