Language Choice

Lets say my non-CS interests lay in Physics, Applied Math, and Mech E, should I focus on high-level languages (Java, Python, etc.) or lower languages (C, C++, and maybe Fortran-ish)?

Also, is there any point in learning the GUI aspect if they are mainly drag and drop with most IDE's (i.e. Netbeans)?

Some fields still use FORTRAN cause nothing else works as well, or fast...