We'll be going from Florence to Lucca by train making a short stop in Pisa to see the Leaning Tower.

We will be using the San Rossore train "station".

At the start of the triangle 4 tracks got to the left and 2 tracks to the right.

I assume the tracks to the right go to and come from Lucca. Is it the track farthest from the station building that goes from Pisa to Lucca?

No need now to figure this out. The correct track for your train to Lucca will be posted at the station.

There appears to be an awning beside the track farthest from the station building. If that's the track then I could avoid crossing the tracks and going to the building.

Unless there's a board posted on the landing beside the track.

Any idea?

I'm pretty sure there is an underpass of some sort, but we didn't use it. I think I saw it on the pedestrian feature on mappy.com or viamichelin. Try plotting a walking route from the tower to S. Rossore.

Not sure what you are looking for or at but last week we took the train Pisa to Lucca and found our spot by going underneath to track #3. It went easily and we got access from the main station. We did freak a bit when we watched several japanese tourists climb onto and over the tracks to get access to our cars--not done where they come from!