I feed just about every sort of veggie you can imagine (avoiding stuff that's toxic like grapes & raisins, which aren't veggies, but need to be avoided).
So what do I feed? Mustard greens, sweet potatoes, broccoli, kale, collard, carrots, string beans, yams, turnip greens, Brussels sprouts, summer squash, bok choy, pumpkin, etc.
I feed very limited amounts of apple, blueberry, peach, banana,& other fruits. I limit fruits because they're heavy on sugar.
Dogs DO digest vegetables, but they have to be processed in some way. Some people grate them. Some freeze them. Some cook them. But it's not true that dogs don't process vegetables at all. I dice and cook all the veggies into a stew. I season with a few spices (rosemary, thyme, basil, a bit of garlic. Definitely go easy on garlic. Too much can cause anemia. One clove per 20 lbs of dog is the absolute maximum). Then I portion it out and freeze in zip-loc containers.
My dogs get a wide variety of vegetables, therefore a wide variety of nutrients. Because each stew is different (depending what is in season), but it gets frozen, I can mix up the batches so they get variety that way as well. And they LOVE it! I mix it with a bit of cottage cheese, and if it's a muscle meat meal, their meat gets mixed in as well. When I put the veggies down next to their RMBs, they often eat the veggies first (even if they're not mixed with anything else)!
I don't use synthetic supplements like a lot of raw feeders do, so I put a lot of thought into my veggie mix to ensure that it provides the nutrients my dogs need. And I like that it does so naturally. I know the produce I buy is mostly organic. And I know how I cooked it. It doesn't come from a pharmaceutical company or manufacturer.
Given that you're starting out with a pup (like I did), your pup will most likely develop a palate to appreciate a wider variety of foods. So he'll enjoy foods that you might otherwise not expect him to! (Some foods, like Brussels sprouts and greens will probably be too bitter to eat on their own, but mixed with yams or pumpkin? He'll likely learn to eat those just fine! And they're so healthy!)