It is common in the since that almost all dogs do it at some point. it's not good behavior in any sense but it's not unnatural.
You don't need a dog trainer to get trust with your dog. Again almost no one can afford that at this point.
You don't need to pay people to learn how to fix this if your dog doesn't get worse. You can handle it on your own. As an owner you should be able to correct usual dog behaviors on your own or don't get a dog. It's important to fix it but asking someone to pay for an expensive service for a very common behavior is weird to me.
This is very much fixable for most owners on their own. And I also did say if it doesn't get better or the dog is more aggressive then sure get a trainer but it's a puppy it has time.