Trail Pass Cinque Terra

Le Anne, where are you seeing this information? There was discussion last last year of possible methods of limiting the daily amount of visitors to the CT (not just the trails) but some media outlets blew it up as a "will happen" versus a "might happen": nothing has been implemented yet.

There is no mention of limitations on the park's website:

http://www.parconazionale5terre.it/Eindex.php

I don't see any current mention anywhere else either so just buy your pass when you get there. The only reason you need one is to hike any section of the Sentiero Azzurro: the famous "Blue Trail". Do be aware that 2 sections of it are closed to damage, have been for some time, and will remain closed through this season. You may hike that one from Monterosso>Vernazza>Corniglia but not from Corniglia> Manarola>Riomaggiore. There are other routes around those obstacles but they're longer and more strenuous: not a problem if you're a fit hiker.

The Sentiero Azzurro is going to be a conga line of hikers in June; just so you know.

Reference this page of the park's website for trail map and current closures, and understand that damage from a heavy storm or falling debris or a temporary instability issue can close any of them at any time.

http://www.parconazionale5terre.it/Esentieri-outdoor.php

Last summer I bought my pass at the train station the day I went hiking, so it should be fine to wait until you get there. The views from the trails are lovely- enjoy!

As I recall, you can also buy the Cinque Terre Park Passes at the small wooden huts at the start of each segment of the trail. I'd suggest starting from the Monterosso end while you're still well rested, as they're a steep uphill climb at the beginning. Be sure to take lots of water.

Seconding Ken here: there are little huts at the entrances to open sections of the Blue where you can buy your pass.