Congratulations on your new snake. Hopefully this experience will go better than the last snake after he has had time to settle in. I understand wanting to save pet store animals because very few stores really know how to care for snakes.
I would start with getting a thermomter and checking your ambient temperature. Unless you keep your house at 80 or more, you will need an auxiliary heat source like a heat lamp.
I didnt have any luck with aspen shavings because it didn’t hold humidity well. Forest Floor or ReptiBark does wonder for humidity. If you get a good gauge like an Accurite gauge, you can keep an eye on humidity and ambient temps. I try to keep my tank between 50-60%
Thank you very much for these tips. However, could I possibly use a mix of peat moss (from Lowe's), sphagnum moss, and orchid bark for substrate as an alternative?