What will happen to the UK once they leave the EU

https://www.politico.eu/article/brexit-cliff-edge-no-deal-departure/

"TRADE

What happens immediately?

Free trade between the EU and U.K. ends at midnight on March 29, 2019 — and both sides fall back on World Trade Organization tariffs.
The combination of such tariff barriers with delays created by new customs checks risks having a severe impact on food supplies and other goods that the U.K. imports from the EU.
Within hours to a few days, the additional costs of tariffs and delays will likely create problems for companies, supply chains and retailers that depend on goods traded with the EU27 — with impacts on almost every sector of the economy.
Prices in shops inevitably rise as a result."