You can link one note to another so related notes are only a click apart. You can also link to any web page the same way.
Linking to another note
Select the text you want to turn into a link, then press CMD + K. In the box that appears, start typing to search your notes by title and choose the note you want, or paste a web address to link to a page instead. The selected text becomes a link.
Editing or removing a link
Click a link to open its menu, where you can edit where it points or remove it. If you link to a note that someone you are sharing with cannot open, it will appear locked to them.
Source: https://support.recollect.fyi/managing-notes/how-to-link-notes-together/