If your pups do not enjoy the company of other dogs, then the dog park isn’t the best place for them. It is important to socialize, but the dog park isn’t the proper place for dogs without social skills. It is not a great learning environment because not every dog is a great teacher.
A better alternative is to have play dates with a family or friend’s dog where you can be in a controlled environment and give the dogs feedback. Letting them loose to fend for themselves will create defensive dogs if they are unsure of themselves, but closely monitored play dates will provide a less stressful situation, and the opportunity to learn.
Some dogs just don’t like other dogs, though, and that’s okay! They’d prefer to be home in their yard.