hi anthony,
the command should be done in global config mode. see below:
Switch(config)#spanning-tree vlan 1 root ?
primary Configure this switch as primary root for this spanning tree
secondary Configure switch as secondary root
Switch(config)#spanning-tree vlan 1 root primary
this command will ensure that this switch has the lowest bridge priorty value, thus making it the root bridge.
are you creating a lab network wherein switches are connected in a triangular fashion?