Amateur radio is a license to experiment, but most operators find their way in through an event: a weekend on the air with a purpose, a table at a hamfest, a park activation, a fox to find in the woods. Nothing here requires a club, though most of it is more fun with one.
Related topics: parks and summits for POTA, SOTA and portable operating; contesting and contests and awards; emergency communications for parades, marathons and storm spotting; clubs and community for nets, build nights and license classes. NARA runs its own week-long, non-contest event — Club Week — built around clubs contacting clubs and exchanging QSL cards.