There are so many ways of how you can spend your summer. During high school, it was mostly spent working a small job such as babysitting and going out with friends. Now that the college years are among us, they are spent either working a full-time job or doing an internship. Those are your only two options as a college student or else you are wasting valuable time.
Being a college student is an all-time job that we need to take full advantage of. That is why during spring semester most students are polishing up their resume, writing cover letters, and searching for internships. Applying for an internship takes time; some require interviews and essays. It is important to be prepared but even the most well-prepared person cannot be hired.
For those that didn't get an internship this summer, still be proactive and do not spend the summer talking about how you "tried." Continue to fill up that resume by looking at other jobs even if they aren't internships. You can still learn so much from other jobs. The important thing is that when you go on job interviews, you can show that you have work ethic by not having spent a summer in your couch.
Not getting accepted into an internship sucks, real bad. But don't let it discourage you from applying in the future. Apply until your fingers hurt, go on as many interviews as possible (you need the practice anyhow).
This is only the beginning of a very long journey, do not get discourage.