If you buy a kit with the SCOBY starter culture and you just need a big container. I bought one of those inexpensive plastic beverage dispensers with a spout from Walmart. One gallon or maybe two.
Making kombucha is like making wine. You need to keep everything clean. It is more or less just chemistry. You need to keep track of the pH level. I think the pH level needs to be down to around <3.5 to be satisfactory. Also temperature control was hard for me in the winter because it needs to be above 65 F for proper fermentation. I bought a pH meter to check it.
I'm convinced it was beneficial following the digestive biotic wipe out caused by heavy duty post surgical anti biotics
