Can I make titles with a black background over another video clip? Any tips for doing that?

Hello! I'm coming from Final Cut Pro, and I'm looking to do some titling over video clips in iMovie and finding it difficult. I basically want to have text on a black background over the video as in the image below.

I'm not seeing any way to get a custom black box under the text, or to put paragraphs in the text. Most of the title options just want to keep it on one line.

Any tips?