firewall interface interconnection

[ravegen]

Good day, I would like to ask for the following.

In the beginning there was only WAN and LAN interface.
There is only the default firewall rule on WAN and LAN Interface.

On LAN interface, the default rule of LAN is Allow Pass from Lan Net any ports to Any Destination any ports. My understanding of this "Any Destination" is "Anywhere". That means, allow traffic Lan net to WAN interface and to the internet. My question here is, with the default lan interface rule, where does the lan net traffic pass to get to the internet? Is it Lan Net -> Lan Address - > Wan Address - > Gateway ?

Now if I have succeeding new interface, let us say Opt1, Opt2, VLAN1 and VLAN2, therefore, "Any Destination" or "Anywhere" will include those including the WAN interface, am I right ? Does that mean that Lan Net can access the opt1 net, opt2 net, vlan1 net and vlan2 net and vice versa ?

But opt1,opt2,vlan1,vlan2 are create without default firewall rules. That this mean that there is no incoming and outgoing traffic on this interfaces yet ?

Moreover, how does opt1,opt2,vlan1,vlan2 get its internet connection from?