There are two different tools with different slots for various projects, one with 32, one with 16, and one with 8. The other slots are used to handle the different complexities of your bracelet.

You can find patterns at:

 https://friendship-bracelets.net/patterns/kumihimo

Here is a tutorial for an 8-string bracelet:

https://artbeads.com/design-studio/kumihimo-getting-started/

Tutorial for a 7-string bracelet:

https://brooklynberrydesigns.com/how-to-make-a-kumihimo-bracelet/

These two are tutorials for the most common types of bracelets to get you started.