My pomeranian is 16 lbs will he be able to win agility and dog show compititions?

There are strict guidelines for show dogs of particular breeds, you should see if your dogs weight is within those guidelines your pommie is very big, I'd do a serious health check before putting your dog through such a serious sustained workout that agility demands. Back to breeding, show dogs have to be specially tested for heart, kidney functions and health and also bone density and hip placement. A few won competitions won't prove your dog is a desirable stud, it can take 2 years before your dog scores enough points to be a champion, there's a lot of ifs, like, can you travel for competitons, it can be expensive, travel, hotels, etc. judges personalities, so much to consider