Find the insert...there's usually a copy online through the manufacturer. It depends on what part of your cycle, etc that you started it during.
as far as i know, a naked penis should be able to enter your vagina pretty much anytime, no matter if or when you took any pills.
it depends on the brand of pill. just call and ask your doctor, don't be shy. or if you are a wuss, wait till you get your next period.
It depends on the pill, if you know which one you're on you should utilize google and do a little research, or contact your doctor, or read the instructions that come with the pills. I've always been told a month.
It depends on why you start taking the pill in your cycle. In some cases, it can start working in as little as 24 hours--but it can also take a lot longer. The insert will give you more info on this