Try this

groups:
      Newb:
        default: true
        permissions:
        - essentials.help
        - essentials.helpop
        - essentials.rules
        - essentials.info
        - essentials.spawn
        - essentials.signs.use.*
        info:
          build: true
          prefix: '[Newb]'
      Citizen:
        default: false
        permissions:
        - lwc.protect
        - essentials.home
        - essentials.sethome
        - essentials.delhome
        - essentials.me
        - essentials.pl
        - essentials.afk
        - essentials.ping
        - essentials.msg
        - essentials.list
        - essentials.nick
        - essentials.mail
        - essentials.mail.send
        info:
          build: true
          prefix: '[Citizen]'
      Owner:
        default: false
        permissions:
        - '*'
        info:
          build: true
          prefix: '&e[Owner]'