Vlans In Pfsense

I am trying to learn how to configure vlans at the moment in pfsense. However some things still puzzle me.

Question 1: When creating vlans what happens to my default LAN on the NIC LAN port?

Will I just plug my switch into my Default lan and make a trunk port? What becomes of the default LAN when you start creating vlans?

My apologies for my confusing question trying to make sense of this.

The default Ethernet VLAN is VLAN 1