I got an automatic a few days ago, only driven it twice, but been extremely easy since the first time. Probably took 5 minutes to get comfortable in it, I've been driving manual for 10 years and the hard part was stopping "muscle memory" of reaching to change gear, moving your left foot to go for the clutch...
In drive, the car will drive even without your foot on the accelerator - it will slowly creep forward. This is nice for driving slowly, e.g. in a car park, you just use the break on its own (gently) to control your speed and don't touch the accelerator until you actually want to go.
It also means that so far at least the car simply will not roll backwards. I have not tried it on a steep hill yet but so far whenever I take my foot off break to move to accelerator I don't get any of the slight rollback you can get from a manual due to being on a hill etc.
Its all a bit strange, unnecessarily expensive (poor mpg and car more expensive) but I can see why people would want them... If you drive a lot, it reduces the work you need to do. I'm only in one cause of my girlfriend.
I'm sure you'll like it, and get used to it quickly, even if you're new to driving.