Right lad - for a first timer I would not recommend traveling by boat for now unless you are going on a package tour. Bus eireann only do anfield trips on a saturday. The boat trip is on Wednesday evening and arrive in Liverpool at 4am, and travel home on Friday evening at 10 to be back in Dublin on Saturday!!! Feck that lad
Ryanair - 450 EURO return - F*CK THAT!!
Aer Lingus
Best option for flights are to fly into Mankchester at 6.30 on Thursday morning and fly out at 11am on Friday - Total is €219 this is the cheapest and safest. There is a train station in the Mank airport. Unfortunately you do not travel near Old Toilet so you cannot p*ss out the window. This train will bring you directly into Lime street in Liverpool. From there you can pretty much walk everywhere, but being your first time taxi's are right outside
Doing it this way you'll be in Liverpool really early, it will be a long day, but being your first time the excitement will keep you awake and buzzing. Trains are about an hour.
The Hostel is the YHA near Albert Dock.
http://www.yha.org.uk/find-accommodation/north-west-cities/hostels/liverpool/index.aspxThey start from £16 per adult.
It will be late at night coming from Anfield after the game so if you do not know your way, there will be buses outside anfield at around 11PM to bring you back to the city - from there taxi's should be found to bring you back to the hostel.
Leave the hostel in good time to get to Lime street train station to bring you to Mankchester airport. Time yoru trains the previous day. If I were you I would head for a train at about 7 - 8.
If you need more info about buses and trains let me know and I'll send you the links but they can be found if search them on the web.
It may seem steep but over the years when you attend many games you will find ways to make your trip cheaper and safer.
Have a good one