Most players will learn them by rote, which becomes the quickest way to recognise them when facing the music.
My suggestion is to use mnemonics - just like we do when learning the line notes on treble clef - 'Every Good Boy Deserves Favour/Football/Flogging...'
I use the same idea to enable students when memorising the string names on guitars. A memorable one is Elephants And Donkeys Grow Big Ears.
So, taking the key names from the circle, we have C G D A E B. With the possibility of omitting C, as it has neither sharps nor flats. Obviously there's F♯ and C♯ to follow if needed - maybe not in early stages of learning?
A six word sentence will do the job - one personal to you, or a silly one will suffice!
Just like the note names for spaces on the treble clef - FACE - we have (F) BEAD (G) to maybe help, or, just make up another mnemonic.
It's a bit of fun, maybe aimed more appropriately at younger people, but it works: still remember Richard Of York Gained Battles In Vain?
Otherwise, by rote generally works - we learned the alphabet that way, didn't we? And there's more in that!