i am going from Bologna to lucca , should i purchase tickets in advance or am i safe in getting them at the station?
You will now likely be safe purchasing them at the station. Bologna Centrale is huge, be sure you fave enough time to find your track.
If you know your travel date and time, you might consider purchasing the Bologna to Florence ticket in advance. There may be super ecomony tickets available for 9 euro versus the base rate of 24 euro you'd pay at the station. Florence to Lucca portion will cost the same no matter when you buy it, and that train won't sell out since it's regional. You can buy the regional ticket together with the Freccia ticket, but it will be prevalidated (good for 4 hours from scheduled departure time).