Hi Jaime, and welcome to MySwissAlps!
>> For the first day I'll plan to go to do the Golden Round trip to Pilatus. Wich segments are not included in the swiss pass.? Where I'll need to purchase in case is needed?
Golden Round trip to Pilatus with Swiss Travel Pass
- Boat to Alpnachstad - free
- Cogwheel train Alpnachstad to Pilatus Kulm - 50% discount
- Cable car and gondola Pilatus Kulm to Kriens - 50% discount
- Bus Kriens to Luzern - free
You can buy a ticket for the cogwheel train/cableway round trip at the valley station of the cogwheel train at Alpnachstad or the cableway valley station at Kriens (depending on where you start). Show them your Swiss Travel Pass to get the 50% discount.
>> Do i need a reservation for the interlaken express?
>> for the hiking/walking from grutschalp to Murren is still snow at this time of year
The snow will probably have melted, but it might have muddy patches.
>> The gondolas and aerial cableway are included with the swiss pass?
>> It is recommended to bring the baby stroller for this day?
Yes, I would say so. I think it would need wheels that can handle some rough terrain.
>> It is possible to do Trummelfach falls with the baby in Lauterbrunnen?
No. Children under 4 years of age can't be taken to the Trümmelbach Falls unfortunately.
>> Gotthard Panorama Express and stay in Lugano. I've already do the seat reservation for me and my wife. Do i need to do a seat reservation for my daughther too?
If you want the option of a separate seat for your daughter, you do need to reserve a seat for her. Otherwise she will need to sit on your knee for the whole trip.
As you have already made reservations for yourself and your wife, you will probably need to make personal contact to get a seat for your daughter that is with the two seats you have already reserved.
I suggest you phone the SBB Rail Service on 0848 44 66 88 to see what can be arranged.