First of all: a warm welcome to the rabble from northern Norway

Pour1malt has given you a good link.

In short, many of the Irish tartans are relatively new (so are Scottish, depending with what you compare...). There are some Irish family names with "own" tartans, but you will see the district tartans are many in Ireland.

Many have a personal relationship to tartans, as in family/geographical connections - and some chose a tartan out of liking to the colours.
The Irish National is always a safe bet...

Good luck - you'll enjoy!