The requirements for travel to Europe vary from Schengen countries to those not included. We talk about the commons, Schengen, while to travel to countries that are not integrated we recommend you ask at the consulate of the country in question.
Of course, to travel in the Schengen area from Spain, you do not need a passport and even less a visa, the DNI in force is enough. And that’s only if you’re going to do it by plane because they’ll require it at the time of boarding. By land, borders and controls do not exist. In any case, you must carry an identification document if requested, for example in hotels. So you have to check that your ID is not expired, take it and travel! Take a look at the travel recommendations of the Ministry of Foreign Affairs and Cooperation of the country you are going to.