In developing a project, talk to your mentors to get a sense of what your day to day duties would be and make sure that aligns with your educational goals. If you choose to get involved in a clinical research project, it can be helpful to determine the status of the IRB paperwork (Institutional Review Board is a committee that approves, monitors and reviews medical research to protect the rights of human participants), since IRB approval may delay the start to project.
No matter how you choose to get involved over the summer, it is good to aim to have a tangible product of your work, whether that take the form of a curriculum you develop, a research paper or poster or case study, an artistic piece, or magazine article. Don't be discouraged if this does not come to fruition immediately at the end of the summer, it is something you can continue to work towards during the remaining medical school years.
This is also a fantastic time to kick back, relax and regain energy. MS1 is a marathon from which you deserve and require recovery. MS2 is an intense sprint for which it is important to be rested. Take plenty of time during MS1 Summer for YOU and those important to you. Dr. Alverson maintains the importance of having "a bit of fun too because its last summer off before the rest of your life".
It is easy to feel overwhelmed by what you might feel should be accomplished in your MS1 summer. Don't fret. Consider your top priorities & ENJOY!