It sounds like the struts ARE functional, which I thought would be the case if it was a SIG kit. This is an important part of the structure, and SIG has good instructions as a rule.

If I were you, I'd write, call, or e-mail SIG and order a hardware package for that kit. It sounds like it was either left out or lost before you were given the plane. If the 1/6 is anything like the 1/5, there are small aluminum pieces you have to bend using a guide in the instructions; two each for the brackets that mount to the fuse at the rear landing gear attach points, two each for the end of the struts where they meet, and two each for each of the ends that attach to the wings. The struts are spruce, you have to cut and glue them together, slot each end and insert the aluminum pieces in the slots, wrap a small piece of 'glass cloth around this connection and epoxy evrything, I went further and pinned them with tiny screws as well.

There should be some brass tubing to make the jury struts from; you cut pieces to length and flatten the ends and drill holes for screws. There are three pieces for each jury strut, and the instructions also contain a cutting and bending guide (full size templates). Without the guides, it would be a best guess how to cut and fit the jury struts; on the 1/6 they might even be made of piano wire.

As for the attach points on the wing, the 1/5 had a long narrow rectangular piece of lite ply that spanned from the front (main) wing spar to the rear spar, you had to measure and drill holes and place a couple of blind nuts ot screw the ends of the main struts to. There were small squares of lite ply that glued to the main and rear spar for the jury struts to attach. Ditto on drilling and blind nuts.

All this was for a 1/5 scale J-3, I can only guess that the 1/6 would be similarly built, but giving exact dimensions would be like a blind squirrel gathering nuts. I really think something is missing from the kit; SIG kits are builder's kits too; if this is your first kit, it's going to be a challenge. Maybe you could swap the kit for an ARF if you really want a Cub--they're fun to fly, but they're NOT trainers.