Cinque Terre Trenord MS card question

Try this (linked through the park's official website):
https://card.parconazionale5terre.it/en/sceltatreno

More about the Treno card from the same official website:
https://www.parconazionale5terre.it/page.php?id=158

Yes, the pass allows for unlimited use of the trails which require it for 2 days: It's valid until midnight of the two days after the day of use indicated on the card. You must, however, reserve a time slot for the Via dell'Amore, and it involves an extra fee. More on this:

https://www.parconazionale5terre.it/Eiti_dettaglio.php?id_iti=3575

"Entrance to the Via dell'Amore can be purchased online and on site, exclusively through the purchase of the Cinque Terre Card Via dell'Amore or as an additional fee of € 10,00 applied to each type of Cinque Terre Card already purchased. For tourists staying in the accommodation facilities of the Municipality of Riomaggiore in possession of the resident tourist card (Guest Card) and staying in the facilities with the CETS Environmental Quality Mark (European Charter for Sustainable Tourism) the additional fee is € 8.00."

That is the site where I am looking to purchase the pass. After reading through it, I was still not clear on what the time slot was for and/or if you need a time to enter the trail. Thanks

Are you trying to buy the "Train card plus" (MS CARD WITH "VIA DELL AMORE)? I can't click all the way through to do a dummy booking without registering but that card looks to be the one the requires the time slot reservation/extra fee for the Via dell'Amore segment of the "Blue Path" (Sentiero Azzurro).

If you've not found it yet, this is can be a helpful companion site to the park's own:
https://www.cinqueterre.eu.com/en/

Thank you for your response. Yes, I am trying to get the 2 day unlimited train access plus the fees for hiking the entire Blue trail. My wife and I intend on getting up early and walking to all 5 towns. I really have no way of knowing when we would be getting to the “Villa dell amore” portion of the trail. It would depend on how long it took us to navigate the trail leading up to that part of the trail. That’s why I am asking what time slot I should choose? Is it the starting time on the trail? Is it the “Villa dell amore” portion? It really doesn’t fully describe what the reservation time slot is for.

Yes, I am trying to get the 2 day unlimited train access plus the fees
for hiking the entire Blue trail.

On this page it is the last option "Train Card Plus"
https://card.parconazionale5terre.it/en

Yes, it allows you 2 days (card expires at midnight of the 2nd day) of hiking the 2 open sections** of the "Blue" (Monterosso to Vernazza and Vernazza to Corniglia) + the Via Dell 'Amore at a pre-reserved time. It also includes 2nd-class regionale rail trips between Levanto > CT Villages> La Spezia.

Be aware that there is still no open section of the "Blue" between Corniglia and Manarola

You must provide a calendar start date for your card at time of purchase. That'll be the first day your pass will be active.

You want the "PN5T MS con Via dell'Amore 2 giorni Adulti Non Residenti" (PN5T MS with Via dell'Amore 2 days Adults Non-residents.) cards UNLESS you are staying in Riomaggiore or Manarola and are in possession of the Resident Tourist Card, then you can purchase the "PN5T MS con Via dell'Amore 2 giorni Adulti Residenti" cards.

Sorry, I don't have a better answer for you but the only "trail" that has any sort of time-slot reservation mandate is Via Dell 'Amore so if it's asking that it'll be the time you're allowed to access that one.

https://www.cinqueterre.eu.com/en/cinque-terre-via-dell-amore

I’m sure we will figure it out. It may be best to just wait before purchasing the pass and ask a few locals. From reading reviews, it sounds like our hotel staff are really good in assisting with things like this.
Thank you for your help Kathy.

You're very welcome. It really wouldn't be such a bad thing to just buy the passes when you get there. :O)
Hope you have a great trip!