Hi Timothy,
Welcome to the community!
It's possible to bring in data from a Google Sheet, but it can be a little tricky to use the data. Scott has some instructions here for how to bring that data into your snippet.
It would be much easier to do this via Data Blaze, since this is the whole point of Data Blaze, though! You can create a table in a Data Blaze space by importing a CSV, and then you can also use the import feature to update existing tables once it has been created.
If you use Data Blaze, you would use the {dbselect} command to retrieve both the ICAO Airport code as well as the proper airport name. You can have the menu display / be searchable by the ICAO code, but the output can be the proper airport name instead.
Let me know if you want to set time up for the coming week to talk this over live, happy to help you configure it. Also pinging @Kevin_Roberts because I'm pretty sure he has created something pretty similar to this already.