Bear in mind that I grew up with the London Underground so my view might be a little biased from familiarity, but on the whole I would say it's reasonably easy to find your way around so long as you've looked at the map and have a
rough idea of where you're going.
Like American highways which are classed as north-south or east-west depending upon their predominant orientation, regardless of whether they actually turn a different direction for several miles, so too are the Underground lines. For example, the Piccadilly line is classed as an east-west line, so even though going from Kings Cross to Cockfosters you are traveling mostly north, you need to head for the eastbound platform at Kings Cross and Cockfosters is regarded as the eastern terminus of the line. Once you have that in mind it's easy to know which platform to turn to when arriving at the correct level for the line in question. Obviously the Circle line is a little different since north/south/east/west don't really have much significance, so the two directions are instead referred to as the Inner Rail (counterclockwise direction of travel on the map) and Outer Rail (clockwise travel).
The other main thing to watch is where a line has one or more branches, so you need to look at the train's destination to be sure it's headed the way you want to go. For example, the Piccadilly line splits beyond Acton Town, so a westbound Piccadilly train might be going to Heathrow or it might be going to Uxbridge, so if the westbound train pulling into your platform is not heading the right way, you'd have the choice of waiting for the next one or riding that train as far as Acton Town and then getting out and waiting for the correct train for the rest of the journey. In the outer reaches, not all trains go the end of the line either, so you'll have similar choices of whether to wait or go as far as you can and change to the next train; e.g. many eastbound Piccadilly trains stop at Arnos Grove, and many westbound trains on the Uxbridge section only go as far as Rayners Lane.
You do also need to keep in mind that the "classic" Underground map is regarded as an excellent piece of design for showing the relationship between lines and the sequence of stations, but is
not a scale representation of the system. The outer sections of track are greatly compressed in distance on the map, and some stations which are in reality quite close together can appear to be farther apart on the map. Some people unfamiliar with the geography have been known to spend 20 minutes taking two different Underground trains and changing between lines to get to a station which was only 200 yards away from where they started!
the modern German tramcars are numbered to continue in sequence from the previous trams built before World War 2
That's kind of nice salute to the past.
I imagine you're familiar with the story of the BTF cameramen who went out and filmed the last journeys in 1952 even though the "officials" didn't deem it particularly important enough to record much for posterity. Lucky for us today that they did so.