Question about Cultivating

I've tried home cultivation before, but it did not work. I under the concept the terrarium, the substrates, sterilization, spores and most other basic things, but I'm having a hard time finding information on one specific detail.

What conditions should the colonizing substrate be in?

Thanks a lot in advance.

around 75- 81 f and in the dark =)

what above said plus a steril environment

that too but thats just kinda a givin haha

I think the Roger Rabbit lets grow mushrooms series is on youtube.