Does anyone know how to zoom in on NetBeans code?

Alt+Scroll Wheel (on mouse) will do it. If you want to change the font size, go to Tools>Options>Fonts&Colors [note: this is a large icon/tab]. From there, in the Syntax tab (default) click Default, then the '...' button next to Font. Change the font size here, and click Okay. Other fonts inherit this size, so that should be the only change.

Happy coding!

press { ALT (your keyboard) + Scroll wheel (your mouse) };