It will land VERY SLOWLY without flaps. They are not really needed. If you want to add them, you can either cut into the trailing edge and add servos in the wing structure directly ahead, or add split flaps made of 1/16th plywood, hinge them and add servos.
Find some members of your flying group that have flap-equipped planes and ask for a look and their explanation.

I only have flaps on Warbirds as these are heavy and have a much higher wing and cubic loading.