Ireland is one of the easiest places to start cycle touring. You get used to riding on the correct side of the rode fairly easily. I have to switch when I rde in Spain or France.
Ireland is chock full of solo cycle tourists who tend to congregate at the independant hostel network. You can usually find one or more people to team up with and its a great way to meet people.
There are bike shops in all the market towns so you dont need to load yourself down with expedition spares.