Lots of great sides for BBQ!
Tomato and Onion Salad - Just slice up some ripe tomatoes and sweet Vidalia onions, then make a dressing (about 1/4 cup olive oil to 2 T of white or red wine vinegar...about a T of white sugar, salt & pepper and toss all together and let marinade for a couple of hours. Serve on a big platter and sprinkle the top with chopped, fresh basil).
You have to do coleslaw with BBQ.
Easiest thing in the world to make. If you don't want to shred your own cabbage, etc., just buy a bag of coleslaw mix. Mix about 1/2 cup of mayo with 2 T or so of white wine vinegar, 1 heaping T of sugar, a little garlic powder salt/pepper to taste and toss with the slaw. I always add thinly sliced red onion to mine, plus a little celery seed and some cayenne pepper (we like it spicy). Tons of recipes online.
Baked/BBQ beans in a crockpot. IMO, not necessary to use dried beans and go through all that...just dump a bunch of cans (drained) of pinto beans (or pork and beans) and add your own spices/sugars. (usually molasses, brown sugar, mustard/ketchup, diced onions, apple cider vinegar, bacon, etc.). Tons of recipes online for ideas....throw it all in a crock pot and keep it on until hot and ready to serve. (Google Baked Beans Recipe Using Canned Beans.)
I've been hooked on this weird salad the last few times we've BBQ'd...sounds weird, but it's so good! Just cut up some watermelon into small cubes, then toss with crumbled feta cheese, very thinly sliced white onion, and a little chopped/fresh mint leaves. Make a little vinaigrette out of olive oil and red wine vinegar, salt/pepper, pinch of sugar and mix well, then pour over the watermelon/onion/mint. You can substitute torn arugula (love that stuff - has a peppery little bite) if you're weirded out by the mint. Yummy!
What about corn on the cob? Just boil it!