My Spark used to render lights in-editor. Did I press something to make it stop? :c

you must have selected "texture unlit" , you will need to select "texture lit" to render the level with lights on.

Where is this option!?!?!

Edit: Nevermind, found it. Select perspective mode and click in the upper left where it says "perspective" and it should bring down a box. Why on earth is it there?

Because lit/unlit controls the viewport you're looking out of