If you have a keyboard with a Windows key on it, push that. It should also toggle you between the start menu and the Desktop.
OK, so now you have 2 or three ways to do anything, instead of just one in Win 7. Not a big deal, just pick the way you want to run, and in awhile it'll all be natural.
Sure, it may take a bit to find how a a few things work initially, unless of course you did an upgrade to an old Win7 system in which case everything should be pretty much in the same places, but once you are used to it, it's all good.
One of the biggest things people have trouble with is shutting down/restarting their systems. Here's a tip or two:
Move your cursor to the upper right side of the screen until the popout menu appears. Click on Settings. From there, Click on Power, at the bottom. There are your restart and shutdown controls. That's also how you get to the control panel and personalization panels.
I can't imagine going back to Win7 and losing the new higher speed of the system, it's just so much faster.