You have the normal entitlement to annual leave. Therefore if your company gives 20 days a year and you are there for 3 months then you are entitled to 5 days holidays over that period.
Are you a self-employed contractor or will you be working as an employee? In the case of the former (i.e. freelance as you have been working up until now) you would not be entitled to annual leave. If you are an employee you would be entitled to annual leave.
My understanding is I’ll be an employee for the duration. I’ll be paid through payroll, with PRSI, etc. taken care of by the employer as it would for a long employee of the company.