Make sure you read the contributing guidelines.
Always branch off of main and use your name in branch name. If you are working together with other developers on a feature and want to each have your your branch, create a feat/{feature} branch.
Explanations written only in the code review tool are not helpful to future code readers. They are acceptable only in a few circumstances, such as when you are reviewing an area you are not very familiar with and the developer explains something that normal readers of the code would have already known. Unless the reviewer's comment was completely incorrect, any non-nit comments should result in a new commit fixing the code, or adding a comment describing the code.
Check out this one if you are new to reviews and PRs Google's Engineering Practices. Or just ship according to PR template.