I wouldn’t recommend starting with Matt Smith or Capaldi. Moffat tried really hard to appeal to long-time fans that most episodes are completely incomprehensible to anyone unfamiliar with the show. The whole extended family was over and we ended up watching that year’s Christmas Special… no one knew what the hell was going on.

I would say starting with the revived show at the beginning, with “Rose”, is your best bet. However, I strongly recommend checking out the original show at some point.