Dag Eva,
It's great that you are coming to Dublin this August with your friend!
Since
renting a car seems tricky in your case, I would suggest using
public transport to go around the island.
While 5 days seems a bit short to see all of the island, you could for instance base yourself in Dublin and go on
day trips (using public transport or tour operators) or build an itinerary across different locations.
I suggest you use the
Transport for Ireland website and the
Rome2Rio website to plan your trip using public transport. Furthermore, here are
trip ideas and suggestions for a
3 days trip right outside Dublin.
Here's also a
search tool for accommodation you might find useful. You can search for hostels and B&B's if you decide to stay in different locations.
Were there some locations you absolutely wanted to see during your time with us?
Groetjes,
Antoine