Get rams or whethers from someone close to your location. Breed isn't terribly important during your learning phase IMO. Raise them to desired weight and harvest them. If you like it, do it again, maybe experimenting with a different breed or a mix of breeds.
Buy from a clean respectful looking flock. Preferably out on grass since that's going to be your approach. If sheep are heavy on grain and you put them on grass they might actually lose weight for a few months while their gut microorganisms adjust--possibly never adjusting well.
Cheap animals are rarely ever worth the price.