Theresa
Brooks (Alberta)
Traveling alone to Portugal in July for 18 days and want to see something (authentic, culture) of Spain, but only have 2 days. this is my first time traveling alone....
Mentioned in this answer:
Portugal is quite a big country and you haven't said where you'll be based, which does make a difference.
There are mountains between Portugal and Spain, which causes problems with train journeys.
For that reason, and given your time constraints, I suggest you investigate the excellent long-distance buses:
Whilst it is possible to take the bus from Lisbon to Madrid it's a pretty long journey. So I'd suggest you get to Faro (an interesting town in its own right) and then take the bus to Seville, a journey of only 1.5 hours.
But your options really depend on where you will be based in Portugal. If you're based in Porto, for example, you might think about taking the bus to Santiago de Compostela.
Official site for train times, details and fares (in English) within Portugal:
https://www.cp.pt/passageiros/en/
Routes, times, details, fares and online booking (if you wish) for long-distance buses within Portugal: