So to start with your final question, it greatly depends on how you define Dreadnought.

The last first generation dreadnought type warship was the German battlecruiser Goeben which was decommissioned in 1950, which in 1914 after escaping to Istanbul had a lengthy career in the Turkish Navy.

Alternatively you have the Iowa class fast battleships Missouri and Wisconsin who served in Desert Storm and were finally decommissioned for the last time in 1992, though all 4 Iowa's had served on and off through the Cold War.

As for the state of affairs in 1914 the Royal Navy had 24 Dreadnoughts in Commission with 5 more building and another 5 ordered during the war. The 24 in service includes 2 that were seized from the yards that had been building for turkey, and she would also buy another one from Chile and another would become the carrier HMS Eagle. And then 10 Battlecruisers, with 2 ordered during the war, 2 semi BC's also ordered and later converted to carriers, and a class of 4 reduced to 1 after the war(HMS Hood).

The High Seas Fleet then in August of 1914 had 17 Dreadnoughts in service, and 4 building of which 2 would be completed. They then had 6 Battlecruisers in services, and would complete 1 more during the war and fail to complete 5 more.

That also excludes the many fine and powerful ships built by other states such as Japan, the US, Austria, Russia, France, and Italy. And the mini arms race in South America. I also only counted ships that had actually begun construction.

I can get into more specifics if you would like, but generally when people ask about 1914 its specifically about the fleets eyeballing each other across the North Sea.