You need an actve device to have vlan working on like layer 2 switch or access point with mmssid and vlan feature.
Create the objects of each vlan interfaces (vlan ip, vlan net, vlan subnet masque, vlan dhcp pool).
Create the vlan interface in the appropriate menu (interfaces/vlans)
create the dhcp for each vlan interface in the appropriate menu (system/dhcp/dhcp server)
Then create an interface group in interface/interfaces group with all 3 vlans.
Then a group of objet using your vlan net object.
then create a nat ip rule using your interfaces group and your object group to access the internet via your broadband connection like
vlaninterfacegroup/vlanobjectgroup nat service wan1/al-nets
Then create another interface group with vlan 10 and vlan 30 and object group with vlan 10 net and vlan 30 net and create a allow ip rule like interface group vlan 10-30/objectgroup vlan 10-30 allow interface groupe vlan 10-30/object group vlan 10-30
that should do the trick