For example,
In any text editor:
Command+right arrow will put your cursor to the Right of the line
Command+left arrow will move your cursor to the Left of the line
Is there an equivalent keybord shortcut for this in Excel for Mac?
You didn't say what version of Excel you're using however see the Moving and scrolling in a sheet or workbook section of Keyboard shortcuts in Excel 2016 for Mac.
FN + Left Arrow
FN + Right Arrow