No, you don't have to tap a creature to harmonize
Magic: The Gathering | Marvel's Spider-Man brings along five different Welcome Decksone for each color of Magic that are tailored toward new players
(Look at the top two cards of your library, then put any number of them into your graveyard and the rest on top of your library in any order.) Daggermaw Megalodon Four generic, two blue creature Shark 5/7 Common Vigilance Islandcycling two generic (two generic, Discard this card: Search your library for an Island card, reveal it, put it into your hand, then shuffle.) Duskmourn's Domination Four generic, two blue enchantment Aura Uncommon Enchant creature You control enchanted creature
We also have a bunch of cards that work specifically with incubate like Progenitor Exarch, Norn's Inquisitor, and Scheming Aspirant
Or you could use cards like Merfolk Looter and pitch big, splashy spells into the graveyard you can flash back for cheap, like Ezuris Predation, Clone Legion, or Insurrection