After a short shopping, togetherrip/After a bit of shopping, I will go with my nephews and my wife will go into the park.

We’ll walk around the lake, drink a coffee - for adults(for the adults, the boys will eat ice-cream). - or "the adults will drink coffee and the boys will eat ice -cream."

A wWalking for an hour will be good forto charged our batteries.

After a short shopping trip, together with my nephews and, my wife and I will go in the park.

We’ll walk around the lake, drink a coffee - for adultsthe adults will have coffee and the boys will eat ice cream.

Better: we'll take a walk around the lake...
To have coffee implies drinking coffee and is how we'd typically express this.

A walking for a hourn hour walk will be good for chargeding our batteries.

Alternative: Walking for an hour...
But you can't say "A walking"