What a beautiful piggie!
If you want to see this little guy have a lot of fun when he's out of the cage in a run, I suggest giving him a paper bag to play with as well as toilet roll. My guinea pig, when he was as young as yours went crazy for his paper bag and would zoom around his cage, into the bag, out of it, zooming around again and back in, popcorning (which is jumps of delight) as he played with it.
As for proofing the room, the worst guinea pigs tend to do is chew at things. Three of my boys are pretty good at not chewing much but one of them has a nibble of everything. The doors, the wires we didn't even realise he could get, the carpet, everything. He loves to chew strange things but not the normal stuff a piggie is supposed to chew, like cardboard. So I suggest covering any wires with towels or pillows or anything that can block and hide them.
His first time out, depending on personality, he might either just hide away and not play at all or he will zoom around. Usually having more than one piggie helps with this problem as the braver one explores and the more scared one eventually sees he/she is okay and decides to brave it too. Of course as you don't have one I think you will just have to watch Charlie and see if he is more timid or willing to explore. However, it won't take him too long to eventually realise its fun to explore and play in the house. =)