This is the practical information page. Have fun.
While speaking Portuguese (or at least trying) will make you lots of local friends, it isn't a requirement. Find anyone under the age of 40, and they will speak some English and maybe they may speak fluently. Currently English is taught as a second language starting from kindergarten, so if in doubt, ask a teenager for help!
Portugal consistently ranks in the top 15 safest countries in the world.
Though Portugal is known for its fish, meat, cheese, and bread, there are an ever-growing set of dining options for you. It may still be challenging to find plentiful options in smaller cities, but in Lisbon and Porto you will have no lack of options.
When traveling as a digital nomad, you should always have health insurance, and if you need care in Portugal do not worry. All doctors will speak English, many will have trained in English, and a portion of nurses will also speak English. Portugal has both private and public health systems, and since doctors that work in one, also work in the other, the only difference between the two is usually the wait time. If you sprain your ankle, you can get treated at both public or private hospitals, but if you are in a rush, it can be more convenient to go private, though you will pay more.
It depends on your style of living. That said, Lisbon remains the cheapest capital city for cost of living in Western Europe, and life around the country is less expensive than you will find in any other Western European country.