For Irish lessons on-lne, the best bet is contacting firstname.lastname@example.org
But start with the phrases and vocabulary here in the Daltaí website (see grammar). Later, a couple of other sites will be helpful, for example, Focal an Lae (I don't have the URL handy).
If eofeasa does not work out for you (or maybe even if it does), you will have to get an old-fashioned book and tapes and learn the way we old-timers did back in the last century. I did a description of available books and tapes just a few days ago -- click on 'Last Week' at left.
There are three dialects of Irish: Munster (southwest), Connaught (west central -- Galway, Mayo) and Ulster (Donegal). All three have areas (known as Gaeltachts as I'm sure you know) where there are still native speakers. People who speak one can understand the others if they hear them enough, but the variation can be quite noticeable.
One difference has to do with the verbs. In Munster, they keep the personal endings (like Spanish). They are used less and less going northward and in Ulster they mostly use verbs without endings (as in English). Another difference is in the way people use the mutations (the sound changes to the beginnings of words that are the strangest thing about Irish for someone who is just learning.) And there is some difference in vocabulary: 'table' is tábla in Ulster, 'bord' elsewhere.
Munster has only about 15 percent of native speakers but a much higher percentage of non-native speakers. Connaught has a little over 50% of native speakers, who use it in many formal situations like economic cooperatives, social events, television and radio, and it is halfway between the other two dialects making it appealing to many learners. Ulster is favored by anyone with connections to Donegal and Northern Ireland. Some textbooks use a standard Irish (an Caighdeán), which has a growing influence even on younger native speakers, but almost everyone gravitates to one dialect or another.
Lastly, see if you can find an Irish speaker one who can help you. A few Irish wind up everywhere, even Peru.