A319 First Officer reported they did not disarm a door after a ferry flight; resulting an inadvertent escape slide deployment when maintenance personnel opened the door.

Narrative

Prior to departure I checked/closed all overhead bins as well as secured all push carts and armed all slides for all 4 doors. Upon landing; I ran the Parking Checklist and moved to the L1 door to disarm the slide prior to maintenance opening the door. They didn't open it so I did. I asked if we had a ride to the next aircraft but was ignored. I then asked if we should shut down completely and they yelled up to us to do so. We then secured the aircraft with the check list. We then departed the aircraft. No one was around. I found another maintainer at a different aircraft and asked for a ride to our next aircraft and was told to walk to the main entrance and go thru security again. So we did just that. Upon arrival at the next aircraft; a maintainer was onboard and said that we didn't disarm the slides and one deployed. Having not ferried aircraft much; I should have familiarized myself with the procedures in the Operations Manual. It was my responsibility to only arm L1 and R1. As well as closing all bins and securing all carts and loose objects. Upon arrival; I am to disarm L1 and R1 prior to performing the Parking check list. I will never make that mistake again.