Of particular interest to employers will be your leadership ability. Be sure to describe any leadership role that you played in your activities, whether it was formal or informal.
I suggest starting your bullet points with action verbs (e.g. Coordinated, Maintained, etc.)
I would encourage you emphasize your community and charitable activities on your resume.
Athletic achievements can demonstrate attributes like dedication, teaming, organization, successful balancing of time, etc. They can provide a nice perspective of a multi-rounded individual with various strengths.
[Include] awards (i.e., State Championship Winner, etc) as this can open the door for discussion in the interview around any leadership experiences you may have learned (i.e., Captain of the xyz Team).
[Don’t use an] inappropriate personal email addresses, twitter handles, etc (i.e. firstname.lastname@example.org)
Under each position and/or internship add your accolades and accomplishments.
Ideally you should focus on the leadership opportunities, accomplishments, and internships you had in college and leave high school off the resume. The exception would be if you had a job or experience in high school that is directly relevant to the job you’re applying for; in that case, you should highlight it.