I was told by admins of a forum that uses discourses back end that I should post this here instead of on their forum.
The forum in question has configured there default join role such that it cannot do anything except read posts. However, you still get the tutorial notification, and based on how its worded it can be construed that it will help you rank up to a rank that can post.
The problem arises when you get to the post a image portion of the tutorial. As you have been denied access to posting images, the forum throws a error every time you try and upload a image. If you know how images generally work online, you can be cheeky and post the image URL of the example picture provided, but that is rather niche. Alternatively you can use the skip command, but the existence of that command is not mentioned within the tutorial.
Apparently changing the text of the discourse tutorial to include a mention of the skip command would require forking the codebase, which is why I was told to post this here.