Rubber bands are helpful clamps here, Just wrap them around the plane. Are the formers square to the sides and square to the top and bottom. Then call it a night, and have some more chilli. If it still looks good the next day then glue it. I use a thin ca for this and then go over again with a thick ca.
Some guys use a wood glue like tite-bond because of reactions to ca's and chilli.
Next the plans will have you add things like stab, elevators, rudder and so on. Don't forget to install the pushrods, servos, battery, and receiver before gluing up the outside. Make sure you can fit a fuel tank in and check the engine mounting. Most guys use a Zona saw to cut the wood and a block sander to touch up the cuts. I like to use those easy touch sanders as they are more rigid and don't flex like the rubber sanders you get at the home centers.