I think "life planner" is pretty vague. Also, you will want to spend a lot of time figuring out how you want it to look or find someone else's and make it work for you. Much more detail required to adequately answer this question.
If by "life planner", you mean something like a calendar or list, just try experimenting with the shapes tool and pen tool to create some basic content areas.
Draw out a rectangle and make the stroke black.
Then Copy it with Command C.
Command F to paste in place.
Alt + drag to create a copy of something.
Hold shift while performing actions like this to move options at right angles.