Hi Wade,
Learning the language of the country you choose to live in is always a good idea and will help greatly with everyday living. Even just knowing enough to understand when the shopkeeper is asking if you would like a bag makes life smoother.
That’s not to say you need perfect Portuguese in order to live here. Many Portuguese do speak English, especially in the Algarve, Lisbon and Porto. And for those that don’t, broken Portuguese combined with their broken English will often be enough to get by.
It’s a good idea to pick up some basics of the language before you move, and you can always study more in depth once you arrive. A word of warning if using apps like Duolingo: often the Portuguese these apps teach is Brazilian rather than European. That version of the language will be understood, but it’s not the correct version for Portugal.
It is almost universally agreed that the “purest” Portuguese is spoken in Coimbra, a riverfront city in the center of the country.
Coimbra is Portugal’s former medieval capital and home to the University of Coimbra, the largest university in Portugal and one of the oldest universities in continuous operation in the world. Its Faculdade de Letras offers summer, annual, and intensive courses (in September and February) in the Portuguese language.
The Portuguese government also offers free language classes for immigrants. These are held at local high schools that run in conjunction with the school year.
There is a detailed section on learning Portuguese in our Escape to Portugal country guide (recently updated by me).