Most reputable breeders will not do a pick of the litter when they can just pay a stud fee. With your dog being 8 most breeders are going to be cautious about breeding with you because of your dogs age, no record of producing, (Not saying that he cant) & not a show dog. A good start is to google information about breeding bulldogs. I think this is the 1st step you need to do. There are also well established breeders in the various forums that you can message. Before I started to breed I learned a ton of information just from a couple members here. You need to know what it takes both financially and medically. After doing all that and you still decide to proceed you should have some health testing done through the OFA.