Blackbird is one of the first fingerstyle songs that my intermediate students learn. It’s one of those songs that looks harder that it actually is. Once you realise it’s a handful of “chord shapes” moved up and down the neck the song gets easier to understand and memorise.
While the fretting fingers I suggest in the lesson may seem challenging at first I think they’re the best choice. However if after a couple of practices you’re finding the middle pinky shape challenging you can use your index and ring finger.
The song has only 2 picking patterns. Both of which are summarised in the intro.
Enjoy and keep on playing.