At first level select cleric, with the nature domain using the feature Acolyte of Nature to select Shillelagh.

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> At 1st level, you learn one druid cantrip of your choice. **This cantrip counts as a cleric cantrip for you**, but it doesn’t count against the number of cleric cantrips you know.
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This cantrip counts as a cleric cantrip for you, so next level up Sorcerer, with the Divine Soul subclass. Select Shillelagh as your cleric cantrip.

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> When your Spellcasting feature lets you learn or replace a sorcerer cantrip or a sorcerer spell of 1st level or higher, you can choose the new spell from the cleric spell list or the sorcerer spell list. You must otherwise obey all the restrictions for selecting the spell, and **it becomes a sorcerer spell for you**.
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Now this spell becomes a sorcerer spell for you. Finally when you have the option to gain a feat, select Aberrant Dragonmark, again selecting Shillelagh.

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> You learn a cantrip of your choice from the sorcerer spell list. In addition, choose a 1st-level spell from the sorcerer spell list. You learn that spell and can cast it through your mark. Once you cast it, you must finish a short or long rest before you can cast it again through the mark. Constitution is your spellcasting ability for these spells.
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If everything is legal, you should have 3 variants of Shillelagh, one using Wisdom, Charisma, and Constitution as their spellcasting ability.

Related: [Can you choose same spell twice from different sources?](https://rpg.stackexchange.com/q/181629)
[What makes a spell being cast considered to be a {class} spell?](https://rpg.stackexchange.com/q/106182)