What to wear to go snowmobiling?

[tomcat19790]

I am going snowmobiling tomorrow, never done any snow sports before. The tour company is providing gear that we have to put on, but I am really unsure what is practical to wear underneath.

Not sure if it matters, but this is an evening ride, so it'll probably be even cooler than during the day with the sun out.

I am concerned about wearing clothes that are too bulky and not being able to be comfortable in the snowmobile gear. I was thinking of jeans and a turtleneck sweater but is that too much? Not enough? How about shoes? Would a pair of tennis shoes be sufficient or do I need something more water resistant?

I know this must sound stupid to some people but I grew up in the tropics, this snow stuff is new to me. Thanks in advance for all your help!