Why only windows?

[mzfr]

Why are you just focusing on teaching reversing for x64 windows? Why not ELF binaries?

[0xZ0F]

It's what I have the most experience with. Also, there are far more reverse engineering and exploit development courses for Linux than there are Windows. I focus on x64 and not x32 because of the same reasons. I will probably talk about x32 vs x64 in the future though.

[mzfr]

okay, I am totally new to these RE courses can you please suggest some courses for Linux?

[0xZ0F]

When it comes down to it, reverse engineering is mostly just being able to read and understand assembly. I would highly recommend starting by learning to write assembly and go from there.
For that, I would recommend:

• x64- https://www.youtube.com/watch?v=VQAKkuLL31g&list=PLetF-YjXm-sCH6FrTz4AQhfH6INDQvQSn
• x86 - https://www.youtube.com/watch?v=wLXIWKUWpSs&list=PLmxT2pVYo5LB5EzTPZGfFN0c2GDiSXgQe.

Here is a great GitHub repo that lists various resources: https://github.com/michalmalik/linux-re-101

You'll want to bookmark a syscall reference source, such as https://syscalls.w3challs.com/.

LiveOverflow has a fantastic course for Linux binary exploitation. It's not strictly reverse engineering, but it's still a good place to learn it. I will say though that the first few videos may be a bit too fast to understand, so you may have to go elsewhere for that information. Here is that course: https://www.youtube.com/playlist?list=PLhixgUqwRTjxglIswKp9mpkfPNfHkzyeN.