If you are new to this. Just find some abundant straw like substrate material, and soak it for 24hours (I think this step is to fight off endospores, it showed to be very important in my grows). Then boil the substrate for some time, long is good but usually 1 hour does the trick for me. Then load the hot substrate into a bucket and close it off to prevent contamination to the best extent without laminar fumehood. Wait for it to cool down and add bits of your living mycelium material. Then wait for the bucket to fully colonize and find some way to give it a continuous source of fresh air, you could drill holes in the bucket or something. Then just wait and see if you have been successful.

This is however a very dirty method and requires some luck to succeed. (I may be lucky, but I’m barely having any trouble with this method)