To get started with the WP Discourse Plugin, go through each of these topics in order and watch the videos at the top of the topic.
The two main plugin features, Publishing and DiscourseConnect don’t have to be used together. You can just set up Publishing (and Commenting), and not use DiscourseConnect, or just set up DiscourseConnect, or set up both. There’s a short description of each feature at the top of their topic.
You may also need to change some of the settings not mentioned in the videos, depending on your setup. All of the settings are explained in their relevant topic, but if you have any questions about them, reply to the topic and someone will get back to you shortly. You may also find these other WP Discourse topics useful, depending on your needs