Streaming shows have had literary tie-ins before, but not quite like this. CBS All Access' upcoming Star Trek: Picard will have two works that serve as lead-ins to the series -- you'll want to read them if you intend to be fully informed before the show's debut. A three-part IDW comic book series, Star Trek: Picard--Countdown, will kick off in November 2019 and center on a mission that will "change the life" of the legendary Starfleet captain. You'll have a better sense of the situation he's in as the online show begins.
A novel, Uma McCormack's The Last Best Hope, will follow in February 2020. It'll be published by Simon & Schuster and introduce some of the new characters you'll see in Picard. You may want to read up, then, especially if you aren't a die-hard fan.
It's far too soon to tell whether or not you'll feel somewhat left out by skipping the books. With that said, the very existence of the titles shows how much trust CBS is placing in Picard. It's betting that there's pent-up demand for a TV show continuing Jean-Luc's story, and it's willing to back side projects that could further fuel the hype.