MacBook A1342 Transferring Data Assistance

Hi all.

I currently have an Apple MacBook model A1342 (late ’09). It’s a school laptop, but as I’m in my final year I am purchasing it off them. They are taking all the software off the laptop, so my question is, is there an easy way to transfer everything that is on my laptop to an external drive? So that after they have wiped it, I am able to safely put everything back on. Thanks heaps.