8 weeks old, and not excited about treats

Yeah no need to worry. When I got my puppy at 8 weeks, he was very picky/unexcited with his treats as well and it felt like he doesn't enjoy them. Give him time, within a few weeks, he will start to love them like other dogs. Make sure to get healthy hollistic treats which have the least ingredients. Otherwise as other stated use your kibble as treats if that works.