Definitely read up on the care sheets as there is a BUNCH of great info in there and some that you might not know about.
You don't HAVE to portion off the tank...but I personally like to..I myself would block it off to half the size and make it bigger as the little guy grows. Makes it easier for them to hunt! But, that is your choice. The baby will do fine in it, just keep an eye on him and make sure he doesn't get too stressed out!
You can feed the little guy crickets (or roaches) whichever one you feed your adult. Just make sure the insect is about the some length as the width between your baby's eyes, so that you know he would have a problem getting them down!
If you haven't already, now might be a good time to look at starting a Dubia colony. They are nice to have when you start having multiple reptiles! Will save you A LOT of money. If you check the for sale section, there is a gentleman in there that sales very well priced starter kits that includes everything you need including Sterelite tubs and heat mat.
Good luck, and check the care sheets in case there is something you didn't know!