The European Commission gets prepared for every eventuality, including a no deal on Brexit. The Commission has launched several legislative initiatives to remedy the negative impact of a disorderly withdrawal in case of no deal.
To get prepared, you can read the Commission's communication on implementing the Contingency Action Plan, its questions & answers and press release.
On their side, the United Kingdom has published an article about classifying your goods in the UK Trade Tariff if there is no Brexit deal.