Hello Marla, I would suggest that you look into any Irish Club or Irish Society in your area. There might be someone close by looking for a travel buddy just like you.
Welcome to the forum Marla. Good idea from Judy. However, if you can't find a travel companion Ireland is pretty easy to do on your own. I have no hesitation about doing things alone in Ireland as it is considered one of the safer countries to visit. Just use the common sense you would anywhere.
Since you prefer to stay in smaller places and get to know people, I suggest staying at B&Bs for multiple nights in each place. You will get to know your hosts and can let them know what your plans are each day. That way they can kind of keep an eye on you if you need help or have any problems.
I suggest you visit my blog. Read some of the articles below but also scroll through for various articles about interesting places to visit. At the bottom of each page you can click on "Older Posts" to view all articles.
Reservations depend on time of year. You mentioned May. The first Monday in May is a Bank Holiday, which means that Fri - Sun will be very busy in most places. May is generally not as busy as "the season" so don't worry about lodging reservations till next year. Airfare: a minimum of 21 days in advance.