Clerks have a lot of administrative roles in their day-to-day job responsibilities. From answering the phone to typing up documents, and even filing and speaking with clients, clerks have a lot on their shoulders.
For the most part, you only need to graduate from high school before becoming a clerk but some clerk positions may require you to complete a certification course beforehand. The majority of your knowledge of the job will come from the on-the-job training you'll be taken through.
You may not have a lot of stress in your day or you could feel a lot of stress, it really depends on what industry you choose to start your career in. Speaking of, you have a lot of options. On the plus side, you'll never work more than 40 hours a week so you can leave work at the office and enjoy your time off.