Like most software developers, Autodesk maintains a list of system requirements for various versions of AutoCAD that can be used to help ensure the hardware in your system will work with AutoCAD. However, most "pc requirements" lists tend to cover the required hardware, not what hardware would actually give the best performance.
When it comes to CPUs there are two main specifications that define the capability of a CPU: 
The frequency directly affects how many operations a single CPU core can complete in a second (how fast it is). 
The number of cores is how many physical cores there are within a CPU (how many operations it can run simultaneously). 
Whether a higher frequency or higher core count is faster depends on how well a program is designed to take advantage of multiple CPU cores. In the case of AutoCAD, the majority of the software is only single threaded so it is only able to utilize a single core of the CPU. For this reason, our general recommendation when choosing a processor is to get the highest frequency. For current generation CPUs, that is Intel's Core i9 12900K or i7 12700K, both of which offer high clock speeds alongside a good number of cores (for multitasking, etc).