Your high school may have a weight-training program, or some other extracurricular fitness program, as part of its athletic department; in addition to signing up for the program, you can assist the faculty who manage it. That way, you can learn about what goes into developing and maintaining such a program. If your school doesn't have a fitness program, seek one out at a community center, or join a health club.
You should also try the services of a personal trainer. By conditioning yourself and eating a healthy diet, you'll get a good sense of the duties of a personal trainer. Any number of books and magazines address issues of health and nutrition and offer weight-training advice. The IDEA publishes several helpful health- and career-related publications including Fitness Journal, IDEA Fit Tips, and IDEA Food and Nutrition Tips (which are available at https://www.ideafit.com/publications).
Seek out part-time work at a gym or health club to meet trainers and learn about exercise equipment and certification programs. Perhaps you could ask to job-shadow them or participate in an information interview with you.
- Aerobics Instructors and Fitness Trainers
- Athletic Directors
- Bicycle Mechanics
- Cancer Exercise Specialists
- E-Sports Professionals
- Exercise Physiologists
- Fitness Directors
- Health Club Owners and Managers
- Jockeys
- Kinesiologists
- Lifeguards and Swimming Instructors
- Physical Education Teachers
- Physical Therapists
- Physical Therapy Assistants
- Professional Athletes, Individual Sports
- Professional Athletes, Team Sports
- Recreation Workers
- Recreational Therapists
- Ski Resort Workers
- Sports Agents
- Sports Broadcasters and Announcers
- Sports Equipment Managers
- Sports Executives
- Sports Facility Managers
- Sports Instructors and Coaches
- Sports Photographers
- Sports Physicians
- Sports Psychologists
- Sports Publicists
- Sports Scouts
- Sports Trainers
- Sportswriters
- Stadium Ushers and Vendors
- Strength and Conditioning Coaches
- Umpires and Referees
- Yoga and Pilates Instructors