Hello Zailallath76
If you travel in the Berner Oberland only, a Berner Oberland Pass could be a suitable all-inlcusive travel pass.
https://www.berneseoberlandpass.ch/
That’s a wrong decision; you are definitely going to miss something if you do not plan a cruise on Lake Brienz or Lake Thun, two of the most picturesque lakes we have in our country. I would rather give Lake Oeschinen a miss.
For train and boat schedules, use sbb-tickets.cc/en or download the SBB Mobile app.
The Berner Oberland Pass is not valid on trains going from Spiez to Visp through the Lötschberg Base Tunnel. You must use the line going via Kandersteg-Goppenstein to Brig.
Kind regards,
Roland