Train travel / and other questions

Hi There,

We are leaving for Switzerland on Friday, 8 June.
I just have a couple of questions, just to make sure we don't get lost or something?
1. We will be traveling from Zurich to Lauterbrunnen. According to the Time Table it look like we are going to take 3 different trains. In Bern and then again in Interlaken. If you miss the first train in Bern, can you took the next one? Just incase we don't make it in 6 minutes to the next platform,

2. We do take our luggage with us on the train? Yes?

3. The train station is at Zurich airport?

4. Where at the trainstation can I validate my Swisspass?

5. Where at the airport can I buy a Sim card for my cellphone?

6. With my Swisspass - at the trainstation at Zurich airport, can we just get onboard the train or is there something else we should do?

Hope you can help me ...
tx
Annamarie

Did I asked to many questions, because you still didn't answer me.