After 31 January 2020, with the ratification of the Withdrawal agreement, the UK entered a transition period, meaning everything remains the same and you can continue to travel as you did before, until the end of December 2020.
The Foreign, Commonwealth and Development Office (FCDO) has published advice on how to prepare if you're travelling to Europe from 1st January 2021, which you can find here - https://www.gov.uk/visit-europe-1-january-2021
This advice includes details on the new rules that will apply for passports. From 1st January 2021, you’ll need to have at least 6 months left on an adult or child passport to travel to most countries in Europe (including France).
If you renewed your current passport before the previous one expired, extra months may have been added to its expiry date. Any extra months on your passport over 10 years may not count towards the 6 months needed so some passport holders will need to have more than 6 months remaining in order to travel. You can check your passport online.
The advice also covers preparing to travel with your pet, find out more now if you're planning on taking your pet on holiday with you, as a new process applies from 1st January 2021 - https://www.gov.uk/guidance/pet-travel-to-europe-after-brexit
