You need to create a source in the "Source" section. A source can be either a web source or an application. Read this page
If you need specific purposes (for example for geolocation or for vendors that are not IAB vendors), you will have to create this extra purposes in the "Purposes" section. Read this page for more information
Once your purposes are created, you need to link them to the source, and then update your notice with your extra vendors list
When all is ready, you just have to implement the "resource url" and/or "html script tag" in your website or your application. Read the "Implementation" section for more information.
You will find all the information you need for this steps in this documentation.