May you help me on what to put for my current security job on my resume?

I just got a security job guarding the high schools during non school hours...you know looking for hazards, suspicious activity, unauthorized visitors, damages, etc. and anything that happens i would report on my daily activity report. Im 19 and this is my first security job so I have no idea what to put to make it sound professional and at the same time make it sound good instead of just saying I patrol the high schools