I usually bring just two rods. Sometimes I bring three, the third is an ultralight set up to have fun with pan fish if I'm not catching any bass. I primarily fish with spinning reels since it's easier for me to cast from a sitting position.
Used to bring a crate, now that's left on a shelf in the garage, as it's added weight and was one more thing to catch the wind if my poles were upright in the attached pvc holders. I have my net behind my seat and a nylon bag (the type that you can put groceries in) also behind my seat. That bag is attached with a clip to the back of my seat with a small diameter rope. Inside that bag is 2 small lunch box size foam coolers. Inside the coolers are two small 8 to 12 oz. water bottles that are frozen and keep my lunch or snacks chilled until they thaw out, at which point they are a nice cold drink.
I start out with the poles rigged up and ready to go, usually one with a shakeyhead set up and the other with an EWG hook to Trig plastics with. I have a small plastic partitioned tackle storage box that holds about 12 lures, including some spinners, spoons and a few crank baits, hooks and jigs. I also bring a few bags of plastic worms and craws. I keep my tackle next to me in a small nylon bag also attached with a clip and small diameter rope to my seat.
I cut up a pool noodle, the kind you can buy at the dollar store, to add floatation to the inside of the bags holding my lunch and tackle, in case they go overboard. I also use about a foot of this pool noodle foam to wrap my anchor rope around and I have a small anchor that has 4 fold out sides,that cost about $10.
Also, I use about 8 " of foam insulation (cut from the grey foam tubes that are used for copper water pipes) and put that just above the reel seat before the first rod guide. It doesn't take much to float your reel & rod,and this has saved me a few times when I have had the pole slip overboard.
I have two rod holders about an arms length in front of me, one on each side. I also keep my needle nose pliers on one side of my PFD and my small camera in a plastic bag on the other side pocket.
As far as extra clothes, it usually warms up, so as I take items off I put them in a plastic bag behind my seat.
I have pared things down over the years so I am taking as little as possible; as I have found that I only use a few things and for me, I am having more fun and keeping track of less stuff.
Good luck in your fishing; with experience, you will find out what works best for you.