Touch

Hold your flat hand, palm out, an inch or two away from your dog.
When your dog sniffs your hand, click at the exact moment their nose makes contact. Then praise your dog and offer them a treat directly in front of your open palm. This placement reward will emphasize to your dog the position they are being rewarded for.
Repeat the above steps until your dog is enthusiastically bumping your palm with their nose. Train in different locations keeping distractions to a minimum.
When your dog has a reliable nose target from a few inches away, you can add a verbal cue like “Touch.” Say the cue right before you present your hand, then click, praise, and reward when your dog touches your palm.
Now you can add distance. Start by moving your hand a few inches farther away. Build up to several feet. Try moving your hand higher or lower, closer to your body or farther away, etc.
Finally, add distractions. Start with small diversions like another family member in the room and build up to larger ones like the park.

I love using touch as a calming exercise. It gives your dog something else other than the stressor.