why not have a holiday in UK first and see how that goes first before going abroad ?
If you go to an island by ferry it feels like you are going further and more of an adventure eg Isle of Wight, Isle of Man, Isle of Arran, rent a cottage, self cater or a static caravan
What about Blackpool has beach and lots to do
Farm holiday
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If you are going to think about abroad
You have to be at airport minimum 2 hours before you fly to check in, so that is alot of waiting around
Secondly, check how far your accomadation is away from the airport. Are the transfers included in your holiday or do you have to pay extra. Do you want to spend 2-3 hours on a bus getting to your destination after a flight. Look for accomodation close to airport
Recommend buying travel insurance the day you book the holiday, incase you need to cancel the holiday
Booking flights mid week and not near any special holidays eg Christmas, Easter, summer, May are always cheaper