On Wednesday there is the photowalk at 11am, starting at HBK. In the evening at 6pm there is the official opening in Penguson Bau. The actual LGM afterwards is in HBK.
About the other questions: I don’t know if you can see your registration details anywhere, maybe mail one of the K8 people, address is on the lgm site. For lunch there will be a catering company, I don’t think that there are real reservations.
If you need to check your registration or your lunch reservation, please send an email to lgm@k8.design. Someone of the local organisation team will answer you.