With a Eurail pass, you can go in any direction you choose, so it all depends on your route. You can go in any direction you want, when you want.
You can hop on and off as many times as you want in a 24 hours period and it only counts as one day.
Here is an interactive Eurail map
where you can use to see what your best options would be based on routes and number of train travel days that you'll need for your trip.