1st event advice needed please

[Miranda]

This w/e will be my first organized event. Ride plan, TBD: either metric century for 67mi, or maybe full 100mi-- probably the metric.

OK... I'm excited and nervous both! Need some misc. advice from my wise TE pals...

1) Do I pack my rain jacket or not?

Weather forecasted atm: 50% chance of rain, high temp 90 degrees F, high midwest humidity, wind speed in the teens mph.

After much reading here, I ordered the Showers Pass Elite II jacket from TE. FedEx shows it will be here today (hope it fits!). I picked this one because it's said to have a nice ventilation system for one thing.

With the high temps, will I even want the jacket on if it's raining? Or not? Part of me says, "... rain might feel good = no jacket", and the other part of me says "...wet chaffed skin / clothes for miles is not good = jacket". Hmmm???...

2) How many tubes / CO2s do I pack?

Routinely, I carry: 1 tube / CO2, and inflate head, patch kit, etc. Basically covers one flat incident. Should I double up? Or is one enough?

3) Are cycling tank tops allowed? Or sleeveless jerseys?

I never really thought about this until I read Bici Mags FitChick's book... at her 1st race she showed up either sleeveless or tank top. The officials said it was against event rules... they made her a jersey w/sleeves outta an event t-shirt to ride. I read nothing against this in my event... just didn't know what was the norm.

4) Should I use the iPod at all or not?

OK... I have read many heated debates on here re: music on rides, or no music. Not stirring the debate itself up, BUT... I personally use right ear bud only on my long rides in the country etc. Sometimes when I'm tired, it's my motivation to pull through. If any other cyclists / traffic are near, I do not use it. I just didn't know if peeps take the tunes on events sometimes or not. Btw, riding alone day one of the event. Thus wondering if I will miss my musical company.

In short, I want to be prepared... but not feel like a total pack mule either. Just looking for some thoughts on a happy balance.

And, Btw... I feel like this is such a big day for me... I've come full circle from sitting here at my computer, ready to stop cycling because I had things bleeding on my body... my first post on TE, "someone please help me!"... all my advice here since has been wonderful... I could not have gotten this far without you, TE!

TYIA!
Miranda