For a novice, one ounce of cannabis may be too much. It offers a lot, which could be intimidating to someone who has never smoked before. Beginners begin with smaller amounts in order to assess their tolerance and level of experience.
It's preferable to start with a lesser quantity—say, a gram, quarter or half ounce—and increase it gradually as necessary. Purchasing weed in lesser quantities also helps save waste in the event that you discover the strain isn't for you. It's important to consume sensibly and gradually.