member level

Hello, when the user registers on a site, his level of standard
how to get standard member so that it is a standard, for example,
31 days is the use full account and, 31 after the member's back to normal standard member,  just certain things that you can use?

Can anybody tell me that please?

You need to enable promotional membership level, then edit that level to allow what you want for the period of time.  Once the promotional period ends, then the member will fall back to the standard membership period.

Update; you will want to enable email confirmation and not automatically activate new members or you will open your site up to spammers heaven.

  I do that but when user register he/she coming stil standart member not that promotional member automatic

Double check your settings.  If possible, take a screenshot and post it so we can see the settings.

 This is  Settings and still user coming standart not promotional