Here is the alphabet that you have learnt about.
a b c d e f g h i j k l m n o p q r s t u v w x y z
I have made a code that means we move $3$ places to the left to discover what the code stands for. By the way, when it comes to A B C being coded they reach back to the end of the alphabet so that the letters go,
v w x y z a b c d e
sdw - d - fdnh
wkh - zhvw - zlqg - eorzv
brx - duh - zrunlqj - kdug
mlpq - qeb - ibqqbo
pnka - qefp - jbppxdb - ql - vlro - c ofbka
You probably could invent some way of coding for yourself that may be like the two above or a bit different.
Please send in your ideas to us.