I think I’m misunderstanding the complaint here. The discord user is annoyed that you are asking for a code review in the first comment? That comment is a valid complaint, as someone who has done code reviews for PRs. Doing a code review can be a very intensive and complicated job, depending on the level of changes being proposed, and the vast majority of GitHub users are volunteers. I sense more of a passive annoyance than any negativity in that comment, and it isn’t directed at you in particular but at the more general annoyance of doing a review.
The second comment doesn’t seem like a complaint directed at anybody in particular to me, more of a complaint about faults in the GitHub UX.
But in general, I would encourage you to consider their perspective. As a project maintainer, I have had to reject proposals, PRs, and give negative feedback to people who weren’t very helpful to the project. I don’t have a personal problem with anybody, and I try to always be encouraging by reminding them that it’s not their skill as a developer I am rejecting, but their specific request. Communicating with strangers is hard, especially with people on the other side of the planet. The person you are responding to is probably looking at several different things that need to be done with the project, sees your code review request, and views it as just another task on a growing pile of work. I guarantee you 100% its nothing personal, nor is it directed at you specifically.
If you have any specific concerns about collaborating on GitHub, like I said, I am a project maintainer, so I can answer questions you have that might be lacking in the Codecademy materials.