CC-licensing your work is simple. All you have to do is choose the CC license that suits your needs and then communicate this choice in a way that will be clear to people who come across your work. As part of this communication, you should include a link to the license you’ve chosen.
This can be as simple as a bit of text stating and linking to the license in a copyright notice, like this:
© 2019. This work is licensed under a CC BY 4.0 license.
…or as complex as embedding the license information on your website using the HTML code associated with the particular license. Use the Creative Commons License Chooser to get the relevant HTML code.