Hi Ciara Kinsella,
You will need to use the trade tariff tool to find the right commodity code for your goods.
Once you have classified your goods, you will need to use the trade tariff tool and check if your goods are covered by a trade agreement.
Also check that your goods meet the rules of origin and what proof you need.
More information on below link:
Pay less Customs Duty on goods from a country with a UK trade agreement
Thank you.