I had a reader send me this and while this young lady and myself would probably loathe one another on most other political issues, in intellectual honesty, I do have to side with her on account that after interning myself THREE TIMES during college, none of them were anything but data entry and filing.
Additionally, since I have a readership that is compiled of younger readers and occasionally I am asked about education, college, "what major to major in," etc., permit me to save you youth some time regarding internships.
Internships depend on the field you're in. Accounting, engineering, sciences, STEM, vocational trades, etc., where even just a year or two of education can result in a skill or a trade that is valuable to an employer is worth it. You'll probably get paid AND (more importantly) get experience.
However, when it comes to the social sciences ESPECIALLY LAW AND "BUSINESS" prepare to just simply waste your time. You will do data entry, reconcile databases, and other stuff people don't care to do while euphemistically being called an "internship." Finance and investing in particular will just make you cold call, fax and be a glorified secretary.
This becomes a problem if (like when I was in college) you have to work for a living and pay for college, rent, living expenses yourself. You simply can't afford to intern if you lose the income at your day (or I guess, "night" job). Ergo, the Ole Captain's advice is this;
Intern only during summer and take on multiple interns. Treat them like dates. At the first sign of trouble ("Oh, there's been a change of plans. We're not ready to start your internship, can you scan in these files for us in the meantime?") you bail on the internship. You won't be learning anything you couldn't have done when you were in the 6th grade. Besides which you have other part time internships scheduled. As more and more internships turn out to be indentured servitude, just leave. Don't even give them a notice or finish the day. Leave.
Hopefully you will find an internship that DOES pay AND gives you experience. HOwever, keep in mind you still have to put food on the table and for the most part (no matter how unfair this is) in the real world employers abuse interns. You simply don't have to tolerate the abuse.