In Ireland having a reference is very important when looking for a job. When you are writing your CV you should always add in the references section “References available upon request”. But you should always have a minimum of two references available when needed.
In Ireland, it’s very unlikely to find a job without a reference. After you have submitted your CV and gone through the interview process, then your references will be requested. Even if your interview went very well, generally you will not get an offer unless you provide references.
Please note if you are from abroad generally you cannot use a reference from your home country. Employers will most often request a reference from someone based in Ireland.
If you don’t have a reference you can already try looking for volunteer work for a short period, two weeks part-time. There are a number of charities in need of office workers. Also there is a big startup scene in Dublin which can provide you with a lot of opportunities.