If you are asymptomatic and seeking a "peace of mind" screen, you can access a free, confidential STI screen via the HSE here. The kits are delivered directly to you, it is free to post the samples back to the lab, and results are available to you within 72 hours of the samples arriving back to the lab.
If you are symptomatic, or if any results from the screen above come back positive, please make an appointment to discuss with a GP.