It is worth noting that Caesar ciphers are vulnerable to a wide range of cryptanalysis methods, especially frequency analysis and statistical attacks, and should not be used for protection of sensitive data.
Instead, use something like RSA/AES for this.
Still, very nice work. Always good to see people learning about cryptography.
Perhaps for a next project you could consider writing software that implements some attacks on a Caesar cipher to demonstrate why they should not be used for protecting sensitive data?
Links:
Practical Cryptography - Cryptanalysis of Caesar Cipher
Wikipedia on Breaking a Caesar Cipher
I will consider the suggestions you have given. Maybe I will do the project you are referring to. Thank you for advising me, and this will be an input for me to develop knowledge in the field of cryptography @shadowey