You do not need to include everything you have experienced, just enough to interest an employer in meeting you in person. The test of a good resume is whether or not you are getting interviews. The process of writing a resume is good preparation for a job search. It encourages you to review your accomplishments and identify those experiences that are relevant to your job target and are likely to interest a potential employer. There is no one right way to write a resume.
Some employers look for evidence of a well-rounded individual.
Others look for a concrete focus supported with relevant experience, while others are impressed with accomplishments that show stability and long term commitment. Some attitudes tend to be occupation-specific. Have your resume critiqued by someone in your target profession. If you are looking for jobs in more than one field, you may need more than one resume. Have your job search narrowed down to a couple of occupational areas based on your career goals, education, and experience.