The booster pack can be from any Magic: The Gathering set, but you must provide it. Consult your co-conspirators for guidance.

To add a booster pack to the draft, first pass the booster pack that contained Lore Seeker to the next player. Then open the new booster pack, draft a card, and pass the new booster pack in the same direction. Then you'll receive the booster pack you would've received had you not added a booster pack, and the draft round will continue. The added booster pack will last a few picks longer than the rest of the booster packs opened that draft round.

Adding a booster pack to a draft may cause some players to have more cards in their card pools than others. This is normal.

If you use Agent of Acquisitions to draft a booster pack containing Lore Seeker, and you wish to add a booster pack to the draft, first draft each remaining card from the Lore Seeker booster pack. Then open the new booster pack. You may look at the cards in that pack, but you can't draft any cards from it. You'll pass the new booster pack as normal. That was very generous of you.