I've seen several posts about linking to headings on other notes with anchors, but is there a way to link to different spots in the same note? I tried using a link from the Copy Anchor plugin, but was still only able to jump to headings if they were in a note that was different from the one that had the link in it.
Yes. If you give an element an ID, say foo (using HTML, I don’t think there’s a way in markdown), you can link to it by making the link's URL #foo.
Example:
<span id="foo">Anchor</span>
[Link to anchor](#foo)
<a href="#foo">Link 2</a>
You can use “Copy Anchor Link” plugin to get the link that used within the same note. The type of link that you’re looking for is LI or LH which are hidden by default. It looks something like this [Welcome to Joplin!](#welcome-to-joplin). To enable it you can check the information on github.
But note that it's not necessary to create span IDs manually. If you use headers (H1, H2, H3, etc.), Joplin automatically creates an internal anchor for each. If you have a header for "Chapter Three", then its internal anchor is "#Chapter_Three". From experimenting, the anchor text is case insensitive and the delimiter char can be a hyphen or underscore, for example "#chapter_three" or "#chapter-three". You could link to it with [Chapter Three](#chapter_three).