If I had one unit each on "Amateur Recital" and "The Papertree" at the beginning of my turn, can I use the hold effect on Amateur Recital to return my unit from "The Papertree" back to base and not trigger the hold effects/hold scoring for "The Papertree"?

No, you cannot prevent the hold effect or the scoring for The Papertree by using the ability from Amateur Recital.

Reasoning

According to the rules of Riftbound, the "Hold" action occurs during your Beginning Phase. At this time, the game evaluates which battlefields you control (i.e., where you have units present) and awards you Victory Points for holding them.

1. Hold Scoring is Simultaneous: When you enter your Beginning Phase, the game determines all battlefields you are holding. You score points for all of them at once.
2. Triggering Hold Effects: Once you have scored a battlefield, its "When you hold here" ability triggers and is placed on the chain as a pending item (Rule 383.4.d.2.a).
3. Timing of Amateur Recital: The ability on Amateur Recital ("When you hold here, you may move a unit...") is also a "When you hold" triggered ability. Because both Amateur Recital and The Papertree are held at the start of your turn, both of their triggered abilities are placed on the chain during the Beginning Phase.

Why you cannot prevent the Papertree effect:

• The Condition is Met: The condition for The Papertree ("When you hold here") is met the moment you enter the Beginning Phase and the game confirms you have a unit present at that battlefield.
• Triggered Abilities are Independent: Once the condition is met and the trigger is placed on the chain, it exists independently of the unit that caused it. Moving the unit away after the trigger has been placed on the chain does not negate the trigger (Rule 383.4.d.2.c).
• Order of Operations: Even if you choose to resolve the Amateur Recital trigger first to move your unit from The Papertree back to base, the Papertree trigger is already on the chain and will resolve normally.

In summary, once you have reached the Beginning Phase with units at both locations, you have already "held" them for the turn. The scoring and the triggers are locked in, and moving the unit afterward will not retroactively cancel the Papertree effect.