1) I click on the link icon, just like before, and need the list of created pages to choose the one to link to. How do I do this?
I tested this and found that you can search for post names within the field in the floating toolbar but it does not yet offer a way to search for pages. I found that there is work in progress to address that and I added a comment to the issue at https://github.com/WordPress/gutenberg/issues/2084 saying that it came up here. In the mean time, opening the page and copying the url so you can paste it into the link toolbar is the best temporary workaround I can think of.
2) Is there any sort of documentation on how to use this? I’ve found a lot on how to code it. I don’t want to code it, just use it.
In general, Gutenberg breaks content down into smaller pieces that can each have relatively important settings and controls either just above the block (the area you are currently editing) or in the block settings sidebar on the right (accessible via the gear icon in the top toolbar.
To add a new block, you can click the (+) icon or just continue to type normally or drag media into the content area normally just like you have in the past.
I searched Google for “how to use Gutenberg” and this article was in the top results: https://www.shoutmeloud.com/tutorial-use-wordpress-gutenberg-editor.html It looks like it has some good basics, including screenshots, which may help you.
If you still have questions after reading the article or if you find something doesn’t work the way you expected, leave another comment here and someone should be able to help you take a closer look!