I just bought a used macbook pro 15" with yosemite on it. I cou l dnt seem to find in oreferences how to enlarge desktop fonts, fonts in general, etc. Really hard to read. Yet i CAN enlarge the icons in the dock. Any help most appreciated.
in the Finder (the main screen), in the menu bar: View>Show View Options, change the text size. there are options in some apps (like mail); shortcuts (like in safari, command + makes a page larger, command - makes it smaller).
in system preferences>general, you can change the sidebar icons.