Tips/help needed for reorganizing a server room with new racks

Hello all,

To clarify, I'm really junior in networking.

After 3 weeks of employment my management asked me to reorganize the server room. The main reason is because they have no clue what is currently still used and what not. Also the server room is consuming too much power to cool the racks so they want an solution that cools within the racks. There are in total 12 racks and I should reduce it to 8.

I've already made an inventory list of what is currently in the server room.
I'm also creating a document in Visio to rearrange all the devices into the new racks.
What should I pay attention to when rearranging the racks?
Any tips on how I should handle the next steps?

Thanks !