Journalistic shots = a clear and obvious subject/center of interest, bold compositions, peak action (the most demonstrative moment of a movement or gesture), a story (juxtaposition of subject and scene, what’s happening and the people experiencing what’s happening; people interacting, emotions, reactions).
Newspapers don’t like printing too much black or high contrast, try to keep your shots bright and balanced in terms of exposure across the frame, or snap a brighter alternative to a must-have but dark shot.
As it’s for a newspaper that deprioritizes single candids/portraits, they want more of a story–unless it literally is the story, like the mayor or a participant, or if they are themselves a story, like a local celebrity.
Look at similar events from past editions if you can, to see what kinds of pictures they ran.
Really try to avoid providing the client with any previews on the spot if asked, they may just want to know if you got a particular shot, if you did, describe it and reassure them that you got it. Maybe that’s just me.
Formally end the coverage with your handler/contact if they are on site, find them or call them (not text) and say thanks, do you need anything else, so they know you’re done or in case they have any last minute requests. If they are not on site I usually shoot an (time-stamped) email or text to say I’m done. I do not ask if they need anything else if text is the only way to communicate.
Whenever you can, get different angles, different framing tight to wide, landscape and portrait, of the same scene/subject, work it thoroughly to give your client options. Frame a little loose for flexibility in cropping.
If some of the event is during daytime definitely get all you can then, it sounds like it might be a challenge to get good stuff after dark, but the parade itself might provide something you can work with.
If you have to use flash, try off camera with a cord or wireless, held as far away from the camera as you can reach either above or at 45 degrees or to the side and pointed back at the subject, whatever makes sense, always higher than their nose (nose shadow should always go at least slightly downward, never up).