Both are under Bulk edits in Meta Ads:

  1. Open Meta Ads and click Bulk edits, above the table.
  2. Select the ad sets.
  3. In the bar that appears at the bottom, open Edit Ad Set.

Advantage+ Audience: choose Advantage+ Audience, select Disable (or Enable), click Apply to all and then Save changes.

Placements: choose Edit Placements. The Advantage+ (automatic placements) option lets Meta decide where to show your ads; Manual shows all platforms and positions already selected so you can deselect what you don't want; Don't change placements keeps what each ad set already has (useful when you only want to change the device targeting).

The automatic creative enhancements (Advantage+ Creative) are on the ads: Bulk edits → select the ads → Ad recommendations → Disable or Enable.