how can i back my iphone in cloud

Hello ~ Take a look here:

How to back up your iPhone, iPad, and iPod touch with iCloud

~Katana-San~

It's more or less done automatically unless you set it up to only update the most important items. I only have the standard 5GB limit and do my primary backup to a Mac. But it still backs up some limited contents of my iPhone and iPad to iCloud, including basic settings.