Grrrrkitty

You do not have to clean anything on first use no.

Some atty's come from the factory with a layer of propolyne glycol on them. It's just used as a priming fluid and is completely vapable. If you want you could blow some of it off from the battery connection end, to help avoid flooding your atty upon first use.

Welcome to the site, and if you have any other questions please post away!

Your tank will be fine with liquid left in it for a week. I've been using the same tank in my eGo-C for over 3 weeks now.