Nope! Many SCA weekend events offer camping, but it is by no means required. There are lots of other options that folks choose that still allow them to attend an event:
day tripping (traveling to an event and returning home on the same day) staying in a personal RV booking a hotel room near the event car camping (yep! some folks opt to bunk down in their vehicles) and more! Before you travel to an event, make sure to check the event website to see what overnight options are available. Not all events have camping, not all support RVs, and some sites are very remote and the hotel selections are slim. Plan ahead so you can get the most out of your event!