Tips on traveling with a 3-year-old?

My husband and I are planning a trip to Barcelona within the next year, and we are excited but a little apprehensive about taking our son, , who would be three at the time of the trip. Our son has never flown, and I’m not sure how he would take it, so one question would be, would it even be worth the risk-taking him? As he would still be too young to really remember anything and a 20hr flight is a lot to ask of anyone, let alone a toddler. Another question would be, what do you do with a high energy toddler on such a long flight? Does anyone else have any experience with this? Thank you in advance! Anonymous Community MemberThis question was asked by a Facebook community member who has asked to remain anonymous.