I need tips on where to stay in Dublin?

Women will want the  blacks 

I don't think they would allow you to sleep in the airport anymore unless you have a flight out first thing in the morning.

There are many hotels and B&Bs in the area around the airport, use the internet to find them. Many even have courtesy shuttle buses for their guests, so you can let them know when you're arriving and there'll be a driver waiting for you.

Sleeping overnight at the airport would be doable, but a complete waste of time.

Think about it. You are woken up the next morning at a very early hour after having had little more than a few snatched naps.

You have nowhere to get a decent wash, private toilet or shower. So then you set off into Dublin and what do you do then? You find a hotel which hopefully will let you leave your bags at reception until check-in time at around 2:00pm. Thus you are now left wandering half asleep and dishevelled and smelly around Dublin for half a day.

Then you go back to the hotel, go to your room and fall asleep for the rest of the day.

Much better to get to your chosen hotel on your night of arrival (warn them that you will be a late arrival) get a good nights sleep and wake up in the morning to a nice private shower, some breakfast and a whole day exploring Dublin. You may have a quick nap, then out into the nightlife and back to your room ready for the next day's flight out.

The airport is a long way from the city center.  Doing sightseeing from an airport hotel would be inconvenient.

I recommend staying at this hotel:

https://www.academyplazahotel.ie/en/

The airport bus stops in front of the hotel. It is about 30 minutes between the airport and the hotel.

https://www.dublinairport.com/to-from-the-airport/...

The hop-on/hop-off bus also stops in front of the hotel.

https://www.dublinsightseeing.ie/

I recommend using the hop-on/hop-off bus for sightseeing via a 24-hour pass, and you can also use it for transportation around the city.

https://www.dublinsightseeing.ie/dublin-sightseein...

If you are not sure what you want to do while in Dublin then consider staying aboard the bus while it makes the whole circuit, which takes about 90 minutes. There is a tour guide narrative, either recorded or from a live guide aboard the bus. Then decide what attractions you want to visit. 

The Guinness Storehouse has a restaurant and a rooftop bar with a great view of the city. You have to pay the entrance fee to get to the restaurant & bar.   The Jameson Distillery has a restaurant & bar that you can access without paying the entrance fee to the museum. The bar in the Jameson Distillery has wonderful Irish Coffee and Hot Buttered Rum.  

You should leave the hotel by about 6:00 AM to ensure getting to the airport on time. There are restaurants at the airport inside the secure area if you want to have a real breakfast before your flight. 

I hope you have a great trip!

Maldron , Carlton or Radisson Blu Hotel are all less than 1 miles from Dublin Airport

Terminal one - best seats! Also food available 24 hours but it will be cold.