That said, Polygon did reach out to ask whether picking a booster pack matters, with the following response received: "While Pokmon Trading Card Game Pocket draws inspiration from the experience of opening physical Pokmon TCG booster packs, we are unable to share specifics at this time." So, essentially, they are unwilling to confirm or deny whether you're choice matters
You can do all the above in any order you wish without ending your turn

Dragon Jungle" #572 "Empress Judge" #573 "Little D" #574 "Witch of the Black" #575 "Ancient One of the" #576 "Giant Scorpion of" #577 "Crow Goblin" #578 "Leo Wizard" #579 "Abyss Flower" #580 "Patrol Robo" #581 "Takuhee" #582 "Dark Witch" #583 "Weather Report" #584 "Binding Chain" #585 "Mechanical Snail" #586 "Greenkappa" #587 "Mon Larvas" #588 "Living Vase" #589 "Tentacle Plant" #590 "Beaked Snake" #591 "Morphing Jar" #592 "Muse-A" #593 "Fire-eating Turtle" #594 "Rose Spectre of Du" #595 "Fiend Reflection#1" #596 "Hungry Ghoul" #597 "Pale Beast" #598 "Little Chimera" #599 "Violent Rain" #600 "Key Mace #2" #601 "Tenderness" #602 "Penguin Soldier" #603 "Fairy Dragon" #604 "Obese Marmot of Ne" #605 "Liquid Beast" #606 "Twin Long Rods #2" #607 "Great Bill" #608 "Shining Friendship" #609 "Bladefly" #610 "Electric Lizard" #611 "Hiro's Shadow Scou" #612 "Lady of Faith" #613 "Twin-headed Thunde" #614 "Hunter Spider" #615 "Armored Starfish" #616 "Hourglass of Coura" #617 "Marine Beast" #618 "Warrior of Traditi" #619 "Rock Spirit" #620 "Snakeyashi" #621 "Succubus Knight" #622 "Ill Witch" #623 "The Thing That Hid" #624 "High Tide Gyojin" #625 "Fairy of the Fount" #626 "Amazon of the Seas" #627 "Nekogal #2" #628 "Witch's Apprentice" #629 "Armored Rat" #630 "Old Lizard Warrior" #631 "Maiden of the Moon" #632 "Stone Ogre Grotto" #633 "Winged Egg of New" #634 "Night Lizard" #635 "Queen's Double" #636 "Blue-winged Crown" #637 "Trent" #638 "Queen of Autumn Le" #639 "Amphibious Bugroth" #640 "Acid Crawler" #641 "Invader of the Thr" #642 "Mystical Sheep #1" #643 "Disk Magician" #644 "Flame Viper" #645 "Royal Guard" #646 "Gruesome Goo" #647 "Hyosube" #648 "Machine Attacker" #649 "Hibikime" #650 "Whiptail Crow" #651 "Kunai with Chain" #652 "Magical Labyrinth" #653 "Warrior Eliminatio" #654 "Salamandra" #655 "Cursebreaker" #656 "Eternal Rest" #657 "Megamorph" #658 "Metalmorph" #659 "Winged Trumpeter" #660 "Stain Storm" #661 "Crush Card" #662 "Eradicating Aeroso" #663 "Breath of Light" #664 "Eternal Draught" #665 "Curse of Millenniu" #666 "Yamadron Ritual" #667 "Gate Guardian Ritu" #668 "Bright Castle" #669 "Shadow Spell" #670 "Black Luster Ritua" #671 "Zera Ritual" #672 "Harpie's Feather D" #673 "War-lion Ritual" #674 "Beastly Mirror Rit" #675 "Ultimate Dragon" #676 "Commencement Dance" #677 "Hamburger Recipe" #678 "Revival of Sennen" #679 "Novox's Prayer" #680 "Curse of Tri-Horne" #681 "House of Adhesive" #682 "Eatgaboon" #683 "Bear Trap" #684 "Invisible Wire" #685 "Acid Trap Hole" #686 "Widespread Ruin" #687 "Goblin Fan" #688 "Simochi Allergy" #689 "Reverse Trap" #690 "Fake Trap" #691 "Revived Serpent Ni" #692 "Turtle Oath" #693 "Contruct of Mask" #694 "Resurrection of Ch" #695 "Puppet Ritual" #696 "Javelin Beetle Pac" #697 "Garma Sword Oath" #698 "Cosmo Queen's Pray" #699 "Revival of Skeleto" #700 "Fortress Whale's O" #701 "Performance of Swo" #702 "Hungry Burger" #703 "Sengenjin" #704 "Skull Guardian" #705 "Tri-horned Dragon" #706 "Serpent Night Dra" #707 "Skull Knight" #708 "Cosmo Queen" #709 "Chakra" #710 "Crab Turtle" #711 "Mikazukinoyaiba" #712 "Meteor Dragon" #713 "Meteor B

(Whenever this creature becomes the target of a spell or ability an opponent controls, counter it unless that player pays 2 life.) : You may cast target Zombie creature card from your graveyard this turn
Having a consistent way to sacrifice your own creatures in this type of build is always important, especially if that sacrifice outlet doesn't cost you mana
Whilst this is definitely going to do more work in a competitive and high-budget metagameone with access to Mana Vault, for example it can still do work outside of this