You can use
XeLaTeX to process your notes.
ctexpackage is used;
xeCJKpackage is called when processing Chinese characters.
The test environment is Win10 + TeX Live 2018. If you are using a Mac/Linux
system and compiled with
XeLaTeX, please change the font in elegantnote.cls with your system font.
Note: If you are using
PDFLaTeX, you do not need to change the font settings.