“New”-queue numbers only matter relative to each other among cards that you want in a certain order. If you have other New cards that you are gathering at the same time, they might matter. Starting at 0 and stepping by 1 is fine – as long as that reflects where you want these cards relative to any other cards.
Don’t tick that – it’s the opposite of what you want.
That option is useful if you want to insert these cards in your “New”-queue before or between other cards. If this is all the New cards you care about, and you’re repositioning all of them, it doesn’t matter.
Other things to keep in mind –
- After you Reposition (Browsing - Anki Manual) the cards, take a look at how it turned out. If it doesn’t match what you want – Edit > Undo will put them back.
- Once you have these cards in order in the queue, make sure that’s how Anki is gathering them for study. Deck Options > New card gather order > “Deck” or “Ascending” (Deck Options - Anki Manual)