Transitioning to full size bed

My son turned 2 last month and we are wanting to transition him to a full size bed. It’s a small platform bed that’s very close to the ground. So we toddler proofed the bedroom completely and are trying to test it out tonight. Anyone have any tips? I plan to have a monitor running but it’s gotta be plugged into an outlet so I’m worried he will pull it out. So should I leave his door open and put a baby gate up? He can’t climb over the gate. I’m torn on what to do. Do I lay in the bed with him to fall asleep or do I just let him play in his room until he makes his way to his bed? He understands directions and can communicate very well. Any tips would be appreciated.