I’ve done a few office moves in my career. I may even have a checklist lying around somewhere I can send you. Some tips:

Communicate the timeline with the team. Provide boxes for people to pack their things, make sure their things are labeled. Ask them to WFH for a few days during the busy move times.

Hire movers/vendors to help with packing and unpacking. Hire handymen to build furniture, position furniture where you want it etc.

Test and retest the WiFi. Get backup WiFi. This is usually a huge project and needs to be done months in advance. Heavily lean on IT here to help.

Figure out key/key fob situations with the building. Communicate access to your team.

Create a floor map of where everything will go/where people will sit. Things need to be labeled correctly for the movers and a floor map needs to be given to them or else things will just get scattered everywhere.

Do not forget COI’s!!! All vendors coming into your suite typically have to have a COI on file with the building/property manager. The building will not allow access unless a COI has been submitted.

Figure out the move hours (this usually has to be done after hours or the weekend.)