It's shallow reading of history to find "lessons" in it. Cases differ and fact sets are never precisely the same, so you can't simply transfer directly from one case to another. But experience is valuable, and it's certainly profit from the experience of others after making allowance for what is different and what is similar.
Germany was -- and is -- the dominant nation in continental Europe. As a continental power it necessarily had to give primacy of place to the army. Resources are always finite and a navy could never get more than the leftovers after the army was taken care of.
Britain, of course, was a naval power. Its army would necessarily take second place in the defense of the island nation. Indeed, it's a truism that an island can only be defended off shore. There are very few cases of a successful island defense if an enemy manages to land on it.
So when the Germans started their naval buildup in the early 1900s it ended up being worse than a waste of resources. Not only did all the treasure sunk into the navy come at the expense of land forces, but it antagonized Britain and drove it into alliance against Germany.
Geography made any attempt at naval superiority for Germany impossible. Britain controlled access to the sea approaches of Germany. British national interests precluded allowing Germany to ever achieve parity in naval power.
If the Germans had restricted themselves to a naval force sufficient to guard their coasts against French and Russian naval forces there's every reason to think the British would have stayed out of the war. With no naval blockade or just the limited blockade the French could have mounted, the widespread suffering inflicted on the German economy. No British entry in the war means no BEF and probably victory for the Germans in 1914 or 1915 at the latest.. And, of course, with no unrestricted submarine warfare against Britain, there would have been no reason for an American entry into the war,.
It seems to me that China's situation a century later resembles Germany's in some ways. Its a rising economic power that is also tempted to expand its clout in international affairs and boost its military. Like Germany, however, China is a continental power with rival major powers that share borders with it. The army always will come first.
Like Germany, as well, the naval geography works against China. All the sea approaches to China are controlled by other countries -- who all have historical beefs with China. And like Germany, a hundred years ago, China's main rival is the world's biggest Navy. Except, of course, China's situation is even more dire. While the British were forced to be satisfied with a Navy as large as the next two combined, the U.S. Navy is nearly larger than all the other navies in the world, combined.
Germany, at least in theory, could over strain the British by building a large enough navy that some other navy would be able to take advantage and strike. The British negated this strategy through diplomacy. It made allies of the other significant navies, including some it had fought against like France and the United States. By the time war came, the Germans stood almost alone at sea.
In China's case the ground is even harder to make up. The US Navy is far stronger than the Royal Navy ever was --and nearly every other significant navy in the world is already an ally. Among the few that are not formal allies, namely India and Russia, there's little reason to think they'd be inclined to side against the US on China's behalf and every reason to expect the opposite.
The bottom line is that any money spent on a blue-water navy is a complete waste as far as China is concerned. The geography, politics and military technology are hopelessly against them. They can't possibly spend enough money to make their naval forces militarily relevant -- but they can easily spend enough to annoy, alarm and drive into alliance their neighbors. There's been a lot of talk in the news lately about China's new aircraft carrier, submarine construction and other naval improvements. While obviously bearing watching, anything China does in this sphere seems like a trip down the road of folly.