Just learn them by rote and commit them to memory. Then print them out and take them with you, because you will always forget.
Again, print the Morse code out and take it with you. If you are having to decode Morse, it means you are indenting a beacon, and if IFR with jepp plates then the Ident is written in Morse right in front of you, so no need to learn anything. If you wanted to learn, the old fashioned audio cassettes are pretty good, I got one off ebay and made the effort, but there really isn't any need.