For general information, please see the Irish Immigration website here.
As a Ukrainian arriving in Ireland you have 90 days before you need to regularise your status. Ireland is an EU country and is working with the EU to activate the EU Temporary Protection Directive, an emergency provision designed to respond quickly and humanely to the mass displacement of Ukrainian people.
Once this is finalised, the details will be made available on the Irish Immigration website. In the meantime, if you require it, displaced nationals arriving from Ukraine can be given accommodation by IPAS. You are also free to source your own private accommodation.