can ANYONE join, really?

hello everyone, i recently saw a sign-up sheet for USMS at my gym and i would really like to check it out but wanted to ask if it really is for any ability. most people who post here seem to have had some formal swimming training, even if it was 10 or 20 yrs ago. i never had a chance to learn from a coach or to join a swim team, i'm not even sure who taught me swimming. all i know about swimming strokes is what one can learn by observation. i usually go to my gym's pool once a week or so and swim laps in what might most resemble a breaststroke. i'm a 25yr old female and i'm in good physical shape otherwise, but i think i might die a little if i were to jump into twice a week two-hour workouts. i greatly enjoy swimming and would really like to join but not sure if my ability isn't just a tad below the necessary level. thank you for any advice!