Want to drive Dublin to Dingle and return, but car rental anxiety!

Sounds like this will be your first experience driving on the left. If that's indeed the case then I agree that picking up the car outside the city center is a good call - you really don't want to start your learning curve on Dublin city streets, which can be daunting even for experienced drivers. Starting your adventure from a car rental agency at the airport, on the other hand, will mean that the first part of your journey will be via the motorway, which we thought was a much easier introduction and helped tamp down the butterflies until we felt comfortable with all of the rules of the road.
Likewise your decision to go with an automatic your first time.
Do opt for the rental company's CDW coverage, and maybe the super cover would be a wise choice to get your deductible down to zero...just to ease your worry about side-swiping some of the scenery along the way.
Will you be driving with a companion? It's always helpful to have an extra set of eyes to help talk you thru the navigation, look for signage, remind you to stay on the left, etc. Something that helped me the first time, and which I continue to do every trip, is to look at Google Street Maps to preview my route each day. Helps me immensely to be able to see the sight picture for the roads in general, as well as being able to study roundabouts, signage, and traffic before I have to negotiate them for real. Works for me, maybe it will be helpful to you.
If you're doing this by yourself I suggest getting a good road atlas (ours was Collins but there are others) and maybe using a GPS that has the European maps installed. For your short trip it might be more cost-effective to just opt for one in your rental. If there's a likelihood that you may return to Europe then just buying your own might be an option.
Don't be in a big hurry to exit the rental car lot when you pick up the vehicle. Take a few moments to familiarize yourself with the car, do all of the usual seat and mirror adjustments, and then take a lap (or 5) around the parking lot just to get used to both the vehicle and the view, then be on your way once most of the butterflies have stopped screaming. It'll be a steep learning curve but if you're already an experienced driver you'll do fine.
There are several rental car agencies at the airport, which has always been our starting point. Others on this forum have recommended Dan Dooley. Might google him to see what rates and conditions are on offer for your particular travel window. And yes - you'll need to catch either a taxi to the airport from Dublin or maybe look at one of the airport shuttles. The Airlink is quite good, but your Dublin hotel can help you organize that.
Good Luck

Grace, after MUCH research and hand-wringing, I found Enterprise in Limerick would allow us to pick up there and return to Dublin Airport. We will airlink into Dublin and stay 2 nights; train to Limerick (from Dublin Heuston). Enterprise will pick us up at the station ("call when you're 10 minutes out"). We'll drive to Dingle for several nights and then drive back to Dublin Airport, sightseeing along the way before returning our car. Limerick worked well for us as we're headed first to Cliffs of Moher, but I know there must be other cities on the Dublin-Limerick train route which would have rental car companies. You might want to investigate that.

It really is amazing how quickly you can adapt to driving on the other side of the road. It helps because you are on the other side of the car. I think your own GPS is best, as you are familiar with how it works, etc.

Even though I drive a manual at home and all over Europe, when in the UK I opt for an automatic. Usually the bigger the rental company office the better off you are with assuring you get an automatic... so usually airport rental agencies are best.

As for pricing, it changes all the time. I would just go to Priceline and put in your location, dates, etc. and see what the rates are. I always book the cheapest, then check back every few weeks, and if the rate goes down, book a new reservation and cancel the first. I never prepay and do not use a consolidator... just go direct to the company. I typically rent from Hertz, Avis, Sixt, etc.

Most credit card insurance will not cover Ireland, but if you have Amex (platinum card) they have an insurance you can buy for $25 ... just need to be sure it covers Ireland.
Tons of people do this, so you can too... just take it easy at first . Lots of the roads in the countryside are not all that crowded, so you should do just fine.

Consider flying Dublin to Kerry Airport. Pick up car there. Drive to Dingle just about 1 hour

Consider hiring a tour guide / navigator to go with you in car for first day