Spores / Mycelium
In the early stage of a mushroom's growth, a spore will germinate on a food source. During germination, a thread-like filament called hypha will sprout from the spore through a germ pore. The single hypha will begin branching off into multiple hyphae, consuming nutrients, and seeking additional food sources. Eventually, the hyphae form a network-like mass called mycelium. The mycelium is the vegetive body or thallus of the fungi. You can grow mycelium by injecting spores on grain spawn or adding them to a nutrient culture called agar. Growing mycelium on agar is a preferred method used by many cultivators. The agar plate allows for the rapid growth, and if the spores were compromised, contamination is easily noticeable in the petri dish.
Acquire spores prints and spores syringes through vendors. However, ensure they are reputable before purchasing.