Try the Gallery of Photography in Temple Bar's short courses as a starting point and get pointers from your teacher there as to what to do more seriously, which could be a big investment and you want to get it right. Ballsbridge College do good hobby nightclasses also which I did and then the teacher there can give advice as to what will suit you next. Hope you find what you want.
I have no idea about classes or schools in Ireland. If you are considering it as a career, you will need people skills and business skills as much as photography skills. Something to keep in mind when evaluating schools.