Get an editor, like FontForge, and draw freely. With it, you can export your font. If you want easier usage, I would recommend using ligatures.
FontForge has friendly guides also: https://fontforge.github.io/editexample.html
Hope this helps 
If you want to do the font even easier, and have the icons you want, you can also consider online tools like http://fontello.com/ or https://icomoon.io
Anyway, the best way is to just search the web, just like this:
http://lmgtfy.com/?q=How+do+I+create+an+icon+font%3F