First, welcome.
If I'm reading your translation correctly, you want to update your computer from Snow Leopard to something that can use iCloud. If so, here's what you do.
I beggin my search looking for how configure time machine and stuck here.
This is a good idea. First you should make sure you have a backup of everything you have. Make sure you have a hard drive picked out to use for Time Machine, and then follow these instructions. There's also a video that can show you what to do, but the audio is only available in English and Chinese…
Once you have a backup, this is how you download an application (or, in this case, Mountain Lion) from the App Store.
When it's done downloading, you'll see this icon in your Applications folder:

Click it and follow the instructions. Simple!