For us, violinists, there is a way which is very easy to remember . 🙂
Look at the violin strings.
There are four of them, from the lowest to highest, G sting, D string, A string, and E string.
The major key with one sharp is G Major.
The major key with two sharps is D Major.
Then, what is the major key with three sharps ?
“A Major !” 😀
Then, four sharps will be…?
“E Major !” 😀
You can relate the name of 4 open strings to the major keys with sharps.
We can start like this. 🙂