The calendar
Arena preorder bundles are already in the MTG Arena store and unlock at set launch on 29 September. Those bundles are digital. They are not a paper booster.
Local prerelease is the first time most collectors handle the cardboard. Paper release follows on 2 October. If a listing says “out now” before that weekend, it is not the English paper set.
What to catalog on sight
Reality Fracture’s collectible hook is the Echoverse pair: one card from the Multiverse you know, one from Jace’s reconstruction, often the same character living two lives. Chandra, Torch of Defiance and Chandra, Chill of Compliance are two cards. Liliana, the Faultless and Liliana, the Repentant are two cards. Wizards’ own Arena bundles name both Chandras and both Lilianas as separate items. Collapse them to one row and the binder is wrong.
Play Boosters, Collector Boosters, and the four-color Jace Commander deck are different products. Commander-only cards are not the Play Booster printing. Serialized and Special Guests cards, when they appear, are their own printings. Look at the three-letter set code on the card before you save it.