Travel insurance is important and you should take it out as soon as possible, in particular to cover for the cost of cancellation or the cost of assistance, including repatriation, in the event of an accident, illness or death.

For some good advice from ABTA see: https://www.abta.com/tips-and-advice/planning-and-booking-a-holiday
Or the Government’s Travel Aware: https://travelaware.campaign.gov.uk/