Do I have to buy a new laptop there? Please answer
You have to buy a new laptop.
You have to buy a new one if your processor is up to date
How can I get 4 processor cores? Do I have to buy a new laptop there?
Yes
only a few can replace the CPU
The cores of a processor depend on the (physically) installed processor. There's not much that can be changed about software. Why are 4 needed? Some processors can achieve higher performance by overclocking
You can't upgrade your hardware with software. Some CPUs have hyperthreading, which means that there are 2 cores but 4 virtual ones. So you can play some 4 core games, but also rather badly than right
