Stay in Dublin and just do day trips?

How much time do you have in Ireland? For sure the Cliffs tour would be a whole day. Between the drive there and back and the time at the Cliffs. If you have enough time, I would look to venture outside Dublin.

A few details are missing here. How long are you in Ireland? Is there a reason you want to base yourself in Dublin only?

Most would suggest a western base as well as Dublin. View Dublin, take a day trip or two nearby, and then take the train to Galway. Visit the cliffs as a day trip from here or the Aran Islands.

Do not base in Dublin and use lengthy public transport rides. You will waste far too much time traveling to and from places.

As it’s the teens first visit abroad give them a proper tour, rent a car and see Ireland’s beautiful countryside up close and personal.

Why Blarney?

If you haven’t booked flight already go open jaw. Fly into Shannon and out of Dublin.

West Coast Of Ireland is one of the most beautiful spots on the planet.

Things and places to see and stay:
Dingle
Gap of Dunloe
Slea Head
Kerry Cliffs at Portmagee
Ring of Kerry
Killarney National Park
Muckross House
Ross Castle and Gardens
Kinsale
Cobh
Rock of Cashel
JeerPoint Abbey
Cahir Castle
Glendalough
Powerscourt
Newgrange

We are only able to go for four nights, want to stay away from a full on tour, thinking of starting in Dublin then working our way towards Galway by train?

I agree with Scythian - keep it simple this trip and don't waste what little discretionary time you have by trying to include anything in the west of Ireland.
Time and interest permitting you might also consider a day trip up to Belfast - fascinating place.

With so few days staying in Dublin is a wise decision. I would not do a day trip all the way down to Blarney (major tourist trap) or all the way over to Cliffs of Moher, too much time on the bus. There are other day trips such as Newgrange or Glendalough that are closer and will be more enjoyable. You could also go to Belfast for a day, but there are many things to do right in Dublin that could use up a day or two, also.

Now that the OP shared their very shot time frame then I concur. Stay in Dublin.

1 day of travel: hour bus or train ride to Northern Ireland. Titanic Museum, St Georges Market and Crumlin Road Goal. Back to Dublin.
2nd day: Bus to Newgrange. Back to Dublin. Wander about. Dinner in Dublin. See a play
3rd day: tour to Powerscourt and Glendalough
4th day: bus to Rock of Cashel. Back to Dublin.

Better?

Thanks very much for all the feedback, it is much appreciated!