Templates can be used anywhere - they aren’t just for certain notes! You can add snippets using the core Templates plugin. Press CTRL+T to bring up the template picker. The selected template will insert where your cursor is. If the hotkey doesn’t work (I think it’s preset) open the command palette CTRL+P and search for template. You do, of course, have to activate the plugin 
Activate here if not already (from the settings/core plugins pane):
The Community Templater plugin is great (I use it for running scripts), but is not necessary for this sort of thing.
Edit in case there’s confusion about what part of your question I’m answering… @I-d-as has it correct - metadata HAS to be at the top to work. I’m only addressing the template question.