I personally wouldn't bring the headset unless you've specifically talked about it and she's interested in it.

1) Ask questions. Discuss the answers. Don't worry if it is a bit awkward. You can Google a list of typical first date questions if you need some ideas.

2) You can test the waters gradually. Move closer, see if she moves away. Casually brush or rest your arm/leg against hers and see if she moves away. Depending on what kind of people you are/what attraction is there you can build from there. Honestly though on a first date you shouldn't be expecting much to happen.

3) You can message her afterwards. "Hey I had a great time, we should do this again" etc etc.

4) You don't need a plan for date #2 yet. Maybe something will happen on the first date that leads you to a good date idea. If it goes well and she agrees to a second date you can always say "I'll message you tomorrow to set something up" while you look for ideas.

5) You're over thinking it. Just wait and see how you get along on your date.

6) Whatever you have shared interests in. Or just something generic and fun like bowling or minigolf. Literally google "Fun date ideas in <your city>" because I can guarantee thousands of other people have had the same question.

7) Never heard of that.