Hi LeShonda Martin,
Have you tried this plugin: https://wordpress.org/plugins/so-css/ ?
This plugin will allow you to add CSS very easy with out having to learn the actual 'command'/code to type. It is very helpful.
Hello Dunhakdis- I have been searching for how to change the sidebar navigation menu color but have had no success. I see how to access Custom CSS but with no code knowledge, I'm unsure what command to put?