I’m starting with architectural photography, could you give me advice on the best camera body, lenses and important features to take into consideration?
You need a large format view camera. The bellows kind, and a couple of lenses. At least a 5x7, or even an 8x10 if you have the cash.
The ability to keep lines straight and perspective correct is why I say a view camera. And I say large format because I believe in the old adage, go big or go home.
Or you can be boring and just get a Canon full frame camera like the 5DSR and a few tilt shift lenses. They are the best you can get if doing architecture as they will help with your perspective correction.
You should spend some time doing research on architecture photography.
Seems like you don’t know anything about it otherwise you would have decent time information already to your question.
This could potentially be the only time I’d recommend full frame specifically. Architecture photography tends to use wide angle lenses and the cheapest way to do this is with 28mm lenses on a full frame camera. Depending on your budget of course.