You're free to edit the duration of title cards in the same way you trim videos - by setting the trim handles to the start and end points. There are loads of templated fonts and background cards to fit different tones. Highlight this thumbnail, then press Text to alter the style and words. This places a new card at the start of your storyboard - though you can drag and drop this deeper into your video if you need it.
To add titles or captions to your video, click 'Add title card'.
