I've always done it the same way. When I get a new snake I'll wait 2-3 days before feeding an appropriately sized meal, wait another 3-4 days before handling. He's more than likely nervous around you but it's best to be persistent with the handling sessions. Keep them small, as you've been doing 5-10 minute sessions. After a while he'll figure it out that you're not a threat. Young balls tend to be very nervous and strike frequently but that will gradually end as they warm up to you and mature. When you're holding him, dont restrict his movement at all unless he's trying to go somewhere you don't want him, then just re-position him. I do agree on the enclosure though. Smaller ones work out best for young snakes. My retic is at the 5 month mark and is already 4-5 feet but insists on cramming herself into this incredibly small hide I have for her.
Best of luck!