According to a few news sources, those in their twenties can now get vaccinated in Catalonia, Canary Islands, Castilla-La Mancha, Baleares/Navarra, and Madrid.

I don't know how accurate that is. It may depend on where/how you book the vaccine. I'm in my 40s and live in Madrid, and only got my first dose last week in the local health center rather than a large vaccine hub, because it hasn't been very well advertised. I assumed I still wasn't eligible.

You should just try booking a vaccine, worst that can happen is the system won't let you.

Right now in Germany vaccines are available in abundance, just today Berlin opened a Drive-In Vaccination Center at a furniture store and at Vaccination Centers in Saxony appointments are not needed anymore [1].

[1] https://www.tagesschau.de/newsticker/liveblog-coronavirus-di...