Congrats and welcome to the forum!
Oooo, for the substrate I just used some spare tiles, or paper, I wouldn't use calci-sand or stuff like that as it can cause a fatal impactation. For Zack, I'm using kitchen tiles and on the rough side.
Good Luck with wratchet, cool and unique name, he'll provide your with hours of fun, enterainment and love, not to mention worry! Good luck and don't forget to ask any questions or queries no matter how stupid!
Good luck,
Rose and Zack.