Is it a bad idea to get a Doberman as a first dog?

No it's not a problem. If the k9 becomes a problem it won't b because the dog is unmanageable it will b because u r not worthy of training such a dog. It's all on u. And how u interact with it. U must b the Alpha not the beta or it will not respect u and become a problem that u can't handle.. But I see no reason why u shouldn't get one. Just remember no dog should b kept in a cage or on a chain 🔗. Except for discipline reasons. How would u like it being in a cage or keep on a chain 🔗 most of the day? If u would do such a thing to a dog then u should never have or own any.. Dobermans r naturally argessive and protective. But also very loyal and loving,To family members, remember that the key to having a great relationship with any dog really is Showing it ultimate love and respect and leadership. U always have to b the Alpha!!!

Really it comes down to whether you have the time, patience, and commitment to train a dog, especially one that if not trained properly is more prone to aggression.