I haven't learned anything about modern physics at the university yet, but next year I will, and in the summer before I thought I would read this book, Six easy lectures from Richard Feynman.
It was first published in 1963, and I guess that's quite a long time ago in modern physics. So I wonder if I should read it, if most of the theories described still stand today.
Since, you haven't started Quantum Mechanics, depending on your country, if you country is like mine i.e. Indian Standard, well it will really work well. The reason would be because on your first year, or at least First Semester itself, you'll be taught the old Quantum Mechanics, which is well pretty much still valid for some conditions. So, it won't be a waste of time, but actually benefit you a lot!
I'd say that the lectures are pretty good and a good read. So you won't waste your time reading that. I think it applies for the US Universities as well.
A comment, below that's a must read and you might miss it:
And additionally, it's not only about the physics itself. It's also about how to think like a physicist. – sagittarius_a
