the summer between your first and second year is your last summer truly off, older and wiser posters speak the truth when say have some fun, go water skiing, climb a mountain
if you want to start building your CV it might be good to get contacts with your home school but i am sure you will meet them soon enough, head off to a part of the country you might be interested in doing residency, do a summer research project there
as on option, try a teaching type job, get away from medicine for a while, it might be a nice break...before you decide, explore all your opportunities