You can produce at least ({3} magic symbol) ({U} magic symbol) ({B} magic symbol) ({B} magic symbol) between sacrificing lands excluding Port of Karfell to Squandered Resources and/or by tapping those lands for mana.
Steps
If desired, activate any number of other mana-producing lands you control by tapping them, adding at least ({1} magic symbol) for each land tapped this way.
Activate Squandered Resources by sacrificing a mana-producing land other than Port of Karfell, adding ({U} magic symbol) or ({B} magic symbol) if possible, or any other type of mana otherwise.
Repeat step 2 until you control no other mana-producing lands except Port of Karfell.
Activate Port of Karfell's second ability by paying ({3} magic symbol) ({U} magic symbol) ({B} magic symbol) ({B} magic symbol) , tapping and sacrificing it, causing you to mill four cards and return Lumra from your graveyard to the battlefield tapped.
Lumra enters the battlefield and dies as a state-based action due to having 0 toughness.
Lumra's enter-the-battlefield ability triggers, causing you to mill four cards and return all land cards from your graveyard to the battlefield tapped.
When the lands enter the battlefield, Amulet of Vigor triggers that many times, untapping the lands.
Repeat.
Results
Infinite death triggers.
Infinite ETB.
Infinite landfall triggers.
Infinite LTB.
Infinite mana lands you control can produce.
Infinite sacrifice triggers.
Infinite self-mill.
Put all land cards from your library and graveyard onto the battlefield.