You need to back the adjusters way off. You want lots of slack. then line up the slots in the lever, adjuster, and lock nut. I'd inspect the cable. If it is sticking you can try to lube it. But I'd err on the side of caution and replace it. I'd also pull the front wheel and inspect the brakes and hardware. Lube the pivot points and mating surfaces where the pivots touch the frame of the shoes and where the frame of the shoes contact the backing plate. Very light on the grease and do not get it on the linings or the drum.