You start working about a week after you get there.
This is what I did when I did my program in 2001.
We checked in (at PI, so that's different), moved into apartments, got IDs, information about when Traditions, other training classes were.
I had 2 days between check-in day and Traditions (held at Chatham then).
Then another day after that before F&B classes were held (food safety, money handling, something else). That took 2 days (I think, maybe 1).
The next day we went to our assigned parks/work areas. Tour of Epcot for me, fitted for costume, met with scheduler, given schedule for the next few days.
The next day started 3 days of training at work location. After that it's just work.