What are the temperatures in your tank? Humidity levels? Those are the two environment factors you'll need to know.
He'll probably spend far more of his time inside his hide than basking on that log. It's what they do. Some of them are more skittish than others, so if you just got him he may tuck himself away in that hide for a few more days until he's comfortable with his new surroundings.
Check the temps and humidity to make sure his surroundings are in good shape. If those are in good shape, he'll come out when he's ready.