Hello Eva,
Thank you for joining our Community!
I'll do my best to answer your questions about public transport in Dublin.
First of all, I'd like to invite you to take a look at this page of the Dublin Airport website, where you can find all
the available options to reach the city centre by bus. You may consider purchasing the Leap Visitor Card, a prepaid travel card that you can use for unlimited travel over your selected time period on a variety of transport services and that you can use for traveling to and from the Airport.
Check out this page to know more about it and where to purchase it.
As for the Dublin Pass, you can purchase it online
from their official website. Once you've purchased your passes, you'll receive a confirmation email with details on how to download and activate them.
With that said, I hope you'll enjoy
your time in Dublin very much!
Let me know if you have other questions or concerns!
Buona giornata!
Valentina