There is no indicator, on the note pane (= all the portion to the right of the notes list) to which notebook the current note belongs. Sometimes we get lost, and the notebook on the leftmost list is off-screen. Maybe those breadcrumbs could come handy here!
^ this is directly above the note, so it's to the right of the notes list. I think it's part of the Note Tabs plugin (been so long since I installed that - absolute must have plugin (along with Favorites and Backup plugins that Jack mentioned) - that I don't remember if this is a feature of that plugin).
As a former Evernote user for the better part of a decade, I agree, Joplin is better in many respects. Wait until you start taking advantage of the plugins - you will have features that were requested by EN users for years, but only fell on deaf ears at EN.
Oh, and since you're coming from EN, you might want to check out the Evernote links replacer plugin: New Plugin for users coming from Evernote ! :)