Although I can't exactly write your bullet points for you since i don't know your background, I can provide you with some high-level overview tips to get you started for writing a resume. I will also include a link at the end for a website that I believe was extremely valuable and crucial to my success in landing jobs thus far.
Generally speaking, the bullet points in your resume should be a combination of responsibilities and achievements that are detail-specific and result-oriented.
I have listed some rules to keep in mind below:
1. Resumes highlight your background AND accomplishment - A critical flaw people fail to remember is that the person reading your resume has no idea about your great accomplishments or abilities unless they are explicitly expressed.
2. Always have someone review your resume - Often times, when you have looked at a document for a prolonged period of time, it becomes more difficult to notice mistakes and think from an outsider's perspective.
3. Outline of a resume
a. Basic info - Name, address, phone number, email
b. Education - School, GPA, relevant coursework, achievements/awards
c. Work Experience - This should be the bulk of your resume where you discuss your prior positions in detail-specific and result-oriented bullet points
d. Additional Experience or Leadership Activities - Anything else you would like to include such as prior employment, volunteer work, leadership positions you have held in the past or current
e. Skills & Interests - List any technical skills you have accumulated (Microsoft Word, PowerPoint, Excel are the basic ones) as well as some activities or interests you have to make yourself seem personable and not a robot.
*NOTE: since you have limited work experience, I would put more emphasis on your externship and then any leadership activities (clubs, associations, etc.) and as well as any volunteer work you have done in the past to demonstrate your leadership, teamwork and learning capabilities. Extracurricular activities would work as well.
Generally speaking, your first interview will consist of them asking you some basic questions about your background, why you're interested in the job, and possibly 1 to 2 situational (behavioral type questions such as strengths & weaknesses, why this firm, etc.) or technical question, depending on the interviewer and the job description of the position.
Just be prepared to walk them through your background (academics, related work experience) and how that led you to apply for the position/why you are interested in the position. Talk about your background in a way where it highlights your interests in the field and in the firm.
Practice practice practice. Go through these questions in your head and have your friends ask you questions to simulate what the interview might be like. You might be rusty at first, but the more you practice, the better you will be at speaking in a confident way about how awesome you are in a very smooth and natural way.
Lastly, I would highly recommend checking out this website, http://member.collegejoboffer.com/info
for more tips, advice and strategies on how to craft a winning resume, dominate interviews and everything else necessary to succeed in landing jobs as I was able to land multiple job offers by incorporating and applying what I had learned to the interview/recruiting process.
Best of luck!