Traditional Irish Music
Allan. If you are a complete beginner you should probably start off with some of the simpler tunes like Dawning of the day, Kerry Polka, Munster Cloak etc working up to some easy starter jigs like The Connaughtmans Rambles, Old John's jig. I play the fiddle and the tuning on the mandolin is the same I assume. Lets see what other suggestions you get
Lonesome Road to Dingle (Brosna Slide), Slieve Russell, Jim Ward's, Scatter the Mud, Musical Priest, Silver Spire. Those are some of the ones I started with when I switched over to mandolin.
Winster Gallop I found to be easy to learn and Salmon Tails down the Water plus as already mentioned, Kerry Polka and Roddy McCorley.
I had the habit of playing all up stokes, I am just about getting used to going up/down, but if I'm not concentrating I slip back to the old habit.