To the OP/Dale
+1 on getting a trainer before you fly the Cub, That said weather you build the trainer or go with ARF,
I would on any butt joints push the point of a round tooth pick through the joint and glue with an alfic thinned wood glue it will give you a much stronger joint, Ca's are great for tacking things together and then go over all joints with a small art brush and thinned alfic glue

Just my 2 pennies worth

Cheers Bob T