I have a yellow lab a little over a yr. and I notice he had a sore on his leg so then I stated to look around at his poop. I noticed some bloody poop. What would that mean?

At a year, likely it is worms. Could be something more serious. I would take him and a sample of the poop to the vet. They have the most effective worm remedies. Many heart worm remedies kill other worms too.