First, make sure that you clearly have sections designated for your education, work experience, volunteer experience, and any affiliations you are involved with. Next, Ill tell you how to fill up those sections so that you need to cut down the information you include instead of find ways for it to fill the page.
In the education part, make sure that you show the school you have most recently attended, along with GPA. Under that, you could include the anticipated graduation date, and some of the classes that you feel are most important to add to the resume. You could even put the sum total of all the AP credits you currently have.
Under the work experience, you should provide each company, your role in the company, and the dates that you were working for the company. Under that you should add 2-3 bullet points showing how you made an impact for the company- try to include achievements rather than job duties.
The volunteer experience section is great when looking for a job while not having much work related experiences. Here, it should be layed out the same as the work experience section. Managers like to hire people that show they have values, care about society, and contribute to making the world a better place.
The affiliations section is also great to build up if you dont have work or volunteer experiences. Have you joined any clubs or academic societies that you would be proud to tell others? What was your position within the group? You can really load this section to show people that you are well rounded and have multiple interests.
Finally, if you still have room on that page, you can top it off with any skills you think you have developed. Preface the lists with "Proficient In" and "Knowledge of" to showcase the skills you have mastered. These skills can be technical, soft skills, or hobbies that relate to what you want to do.
Hope this helps you fill up your resume. Good luck on the job search, and remember that finding a job will take some time to network, apply, and on board. Stay positive on the path to your next job!
edit* reading your question again, Do you need to put in a resume? I assumed that you meant what do you need to put in a resume? If you are just asking whether you need a resume, I would say definitely have a resume, it would never hurt your chances of scoring a job.