Hi there, nice sunglow you have there.
I suggest seeings you're new to it, you should keep him as a pet for at least a year and get to know your snake before you make any plans to breed him. Are you even sure it's a him?
You say your snake is 'almost mature', but if you're talking about sexual maturity...he was there a long time ago!
He might choose to hide under the substrate to get to a cooler or warmer area if his home is not odffering him the right conditions.
Show us some pics of the snake...oh, and put the hide back in, he might want to use it sometime, just not today.
Show us some pics of the viv too and we'll perhaps coach you on your settup.
One more thing to note is the various areas to post various questins in this forum. There is one specifically for breeding and one for the cultivars as well as one for newmember introductions.
Good luck