how can we customize and create a new center for a specific role?

Customisation > Centres and Tabs > Centres. If I remember correctly, you need to set the centre when creating the custom role.

Thanks @ryanhowson, but how can I customize classic center instead create one from scratch?

You can open tabs/categories and edit anything custom. You can't customise anything set by NetSuite.

Is it possible to customize dashboard for a scpecific role?

Yes, using Publish Dashboard under Settings. You can only publish dashboards to roles which are on the same centre as the role you are using. I recommend adding the publish dashboards global permission to your user too.

Thanks