2) Do I need a passport?

Yes, you'll need a valid passport to travel with TUI. EU nationals may use their National Identity Card to travel within the European Community, but we recommend you use a passport wherever possible. You'll need to use a passport if you're travelling outside of the EU.
British Citizens must hold a valid 10-year passport. If travelling to the EU, Switzerland, Norway, Iceland or Liechtenstein from 1st January 2021, your passport must be less than 10 years old and will also need to have at least six months validity on the day of departure. UK Citizens can check out the www.gov.uk
 website for passport, visa and health information. Other nationalities should check with their own governments.

To apply for your first passport or to renew an old passport, you'll need to make an appointment.  To do this, call the Passport Advice line on 0300 222 0000. Calls are charged at the local rate.
If you don't have a UK passport, you should always check with your own embassy, high commission or consulate before you book.
Just so you know, it's your responsibility to comply with all passport, visa and other immigration requirements for the country you're visiting. Your passport and travel documents must be intact, too. You may not be allowed to travel if they're damaged or they've been tampered with. We don't accept any responsibility if you can't travel because you haven't complied with the requirements.

Going to Turkey?
Just so you know, for trips to Turkey your passport may need to be valid for longer than 6 months after you return. Take a look at our 'What are the entry requirements for Turkey?' FAQ for more details.