All dogs need training, but after a certain age, they're trained and the training keeps going just by being consistent, so it's low effort. It might need readjustment, but it's not hours everyday.
All dog owners have been first time owners, there's nothing wrong with that, I really don't get the gatekeeping here.
Puppies are hard work though, and can be very frustrating, we all have this image of the snuggly puppy but the reality is more one of a furry terrorist with sharp teeth who finds many creative ways to get into trouble.
In puppy stage, everything requires training. Toilet, being alone, jumping on people, biting, barking, walking on the leash etc...
People often confuse training with commands (like sit, go to your bed etc...) Commands are useful, but training is much more than that, it's about shaping the dog's behaviour. Most aspects of training won't have a command attached to it.
Is it hard? not really, it's not rocket science and there's loads of very very helpful resources (professional trainer, books, podcats, videos etc...) but it's relentless, it feels a bit like a game of whack-a-mole, there's always something new to address. And it requires full household alignment. I personally always trained my dogs alone, so I never had that issue but I can imagine it creating tension in the family!
This said, as hard work as puppies are, they grow into dogs, which are fabulous companions, so it's 100% worth it!
My puppy is not a puppy anymore, 18 months old, his training is still ongoing, and I foresee it'll be for a while, but the bulk of it is done, and he's a joy to be around, when I look back at how much of a dickhead he was 12 months ago, I have a hard time wrapping my hear around the fact that it's the same dog.
And yes, they are not cheap.
Breed wise, I'd say a border terrier would be a good candidate, they are fantastic little dogs, compact but sturdy and generally very well natured.
Same for cairn terrier or westies.