Back in 2016 we planned a 60 day trip to Europe across dozens of cities, that included planes, trains, cars and boats. It was done in google spreadsheet. Very convenient to plan, not very convenient to use on the road.
After years of traveling we switched to the following model:
Draft plans: Shared apple notes with the name of a country / City
Then I forward all confirmations to tripit to categorize and create a meaningful calendar feed. It worked a bit better for me then Kayak trips, but that was long time ago.
City Tours - Google Docs or Apple Notes & google map routes