A fellow writer/editor recently commented that she knows in the first sentence if a piece is going into the maybe or the no pile.
Like a "whoop" whooped on a canyon floor, I echo her statement. First paragraph for me, though.
That's not to say editors don't read the whole piece before exercising the sorting hat's decision, because we (almost) always do. Yet, the similarities in process from the diverse editors I know (and know of) should give all serious writers pause.
Readers don't owe us their time. We have to earn it, sentence by sentence.
Pull out your favorite pieces of writing by others. Copy the first sentences into a notebook or a single Word doc, and consider them as a whole. Study them. Analyze. What do they have in common? What do they NOT have in common?
Then look at your first sentences. Are you beginning well?