Atocha Train Station

Don't worry most customers service personnel speak English and information is in English French and Spanish. There are customer service counters. Arrive an hour before. All bags go through the x-ray machine. Just like the airports there are big departure boards with the all the trains listed in order of departure time; closer to departure the track or platform will be listed.

I don't consider Atocha as overly large. A lot of it is the entry with conservatory garden, but it iseasy to know where the entries to the tracks are, and as mentioned, a large info board.
If you can manage big airports, this will be a piece of cake.

I’ve gone through Atocha many times, and while it never quite makes sense to me, I always end up exactly where I need to be. I think targeting to arrive at the station 30 mins before the train departs is fine. I’m sure there are video tours of the tpstation if that might make you more comfortable. “Road trip to Spain and Portugal” on YouTube has a lot of good content like that.

Track assignments are only called 10 mins or so before departure, and there will be a chaotic rush to make a long line to get tickets scanned and access the track. Relax—everyone in the line will get on the train, and you’ve got reserved seats (I presume).

The security check is to access the waiting area for the long distance trains, so there’s time and space to wait after that. And the checks aren’t anywhere near as intense as at an airport.

There are two sets of platforms: Planta Primera and Planta Baja (lower level). So once you know your platform number, there's the additional step of determining if it is within the upper or lower bank of platforms (and finding it!). Even with good signage and helpful people, I'd give yourself a few extra minutes.