OpenCL-Guide VS OpenCL-Headers

Hey everyone, like the headline says I want to learn how to use OpenCL but I don't know where to start. I have some programming experience (Rust, Python, Pascal) but I don't even know how to install the requirements for OpenCL (let alone what they even are), mostly because most tutorials and guides are 7+ years old and the information from Krohnos themselves isn't ready yet (https://github.com/KhronosGroup/OpenCL-Guide). If you have any advice how to start with OpenCL 3.0 please let me know (maybe it is alright to follow the tutorials for OpenCL 1 or 2 after all).

Khronos has today released the OpenCL 3.0.14 maintenance update that introduces a new cl_khr_command_buffer_multi_device provisional extension that enables execution of a heterogeneous command-buffers across multiple devices. This release also includes significant improvements to the OpenCL C++ Bindings, a new code generation framework for the OpenCL extension headers, and the usual clarifications and bug fixes. The new specifications can be downloaded from the OpenCL Registry.

Basically, it is harder to start without vendor SDK, but it is totally possible. If you have a device with claimed opencl support the only thing you have to install is their vendor-provided driver. Usually (95%) that will provide you an OpenCL.dll / libopencl.so which you can load dynamically, get address of needed API function and use that in your code. To develop from C/C++ environment it is enough to have dynamic library in your system and https://github.com/KhronosGroup/OpenCL-Headers from here.