Tanks size will depends on the animal size if your snake is 50 grams or under you want a 6 quarts tub or 5 gallons tank.
As for an adult male or female will do fine in a 20 gallons tank.
As far as beeding coco husk such as bed a beast is a great substrate, absorbent but also allow to promote hognose natural behaviour.
Now keep in mind coco coir comes into a break that you have to break by soaking in water and because of that you need to give it time to dry before used once broken up.