I'll rephrase it.
Is there any limitation on the number of instances/objects that you can create in
Java? It is the same thing. The Spring definitions is just that, a definition that tells Spring what to instantiate for you.
By default all beans are Singleton, which is a great thing. And Spring instantiates them when you create an ApplicationContext instance. So the creation of the ApplicationContext might take a little bit of time, but really very small, but no performance issues later. If you find performance issues, it is probably because of your Heap configuration. Which would be a performance issue for you whether you were using Spring or not.
Good Luck and enjoy your trip in learning Spring. My first lesson for you is it is just called Spring. There is no pluralization to it. No such thing as springs.
Also, as you are learning, please post your questions here, we love helping people out.
Mark