"<< Is there a beautiful train that stops in a countryside where there is a small station we can get down, walk into the village enjoy the nature privacy and quiet atmosphere.">>
Country villages do not., however, tend to have active nightlife, which you asked about earlier.
And, in the mountains, nice walks with nature tend to involve a bit of climbing.
A specific trip you could take from Luzern into the Emmental countryside would meet your dscription. Go to Trub (near Langnau in Emmental) , as detailed below.
Some of the countryside nearby this/these village/ villages is discussed in a separate thread about Langnau, with some pictures illustrating the region.
Here is the route to meet your request. There are many, many others.
Take the train from Luzern to Trubschachen, in the Emmental.
Get off, catch the bus to Trub.
Get off, admire the village. Possibly eat there.
Walk back to Trubschachen..
Take the train back to Luzern.
For a picture of Trub, and of an old inn in Trubschachen, look at the pictures in the second post in the thread noted above.