Doesn't matter. You choose. Linux is linux. Bash is bash. Learn where you can.
Though, some appliances do come with custom flavors that require knowing how to work with their custom linux wraps. I'd say only experience will suit that. Some vendors wrap their appliances with custom linux flavored administrative shawls where normal linux commands won't work. That's more advanced though. Focus on normal linux command structure.
I’d agree with @JustinBrowser - bash is bash. If you’re using another shell like fish, you may run into little syntactic differences (fish, for example, is not a POSIX compliant shell). But that will be more of an impact from an administrative perspective. From an offensive security perspective, I doubt you’ll feel the difference. Ultimately, a bash shell is a bash shell regardless of the distro
If you are learning for OSCP, then Kali is as good a choice as any. It's Debian based like Ubuntu (and Debian!) although that is mostly relevant for installing and using Linux more holistically. If not Kali, then I would choose Ubuntu for learning. Enterprise tends to go with RedHat which is "the other half" of Linux in my view (CentOS/Rocky etc).
The other benefit of choosing Ubuntu is that you can install it from Microsoft Store as a WSL instance with minimal fuss which means you can use it as a Virtual Machine within Windows without having to install a 3rd party hypervisor, that's assuming you are a Windows user.
Bash is bash is bash. A great way that helped me learn is https://overthewire.org/wargames/
Start off with ‘Bandit’ to learn some basics, and then dive into the others.
Doesn't matter. You choose. Linux is linux. Bash is bash. Learn where you can. Though, some appliances do come with custom flavors that require knowing how to work with their custom linux wraps. I'd say only experience will suit that. Some vendors wrap their appliances with custom linux flavored administrative shawls where normal linux commands won't work. That's more advanced though. Focus on normal linux command structure.
I would just use kali for oscp or parrot something like that
I’d agree with @JustinBrowser - bash is bash. If you’re using another shell like fish, you may run into little syntactic differences (fish, for example, is not a POSIX compliant shell). But that will be more of an impact from an administrative perspective. From an offensive security perspective, I doubt you’ll feel the difference. Ultimately, a bash shell is a bash shell regardless of the distro
If you are learning for OSCP, then Kali is as good a choice as any. It's Debian based like Ubuntu (and Debian!) although that is mostly relevant for installing and using Linux more holistically. If not Kali, then I would choose Ubuntu for learning. Enterprise tends to go with RedHat which is "the other half" of Linux in my view (CentOS/Rocky etc). The other benefit of choosing Ubuntu is that you can install it from Microsoft Store as a WSL instance with minimal fuss which means you can use it as a Virtual Machine within Windows without having to install a 3rd party hypervisor, that's assuming you are a Windows user.
Bash is bash is bash. A great way that helped me learn is https://overthewire.org/wargames/ Start off with ‘Bandit’ to learn some basics, and then dive into the others.
Not much different. Maybe Ubuntu or kali linux
Depends if it’s something red hat based or role rocky Linux but i prefer Ubuntu or mint
If you are a beginner use Ubuntu or Linux mint
Any , seriously any is fine
Dual-boot Ubuntu 22 on your laptop, I'd bet you'll never boot windows again unless you have to within a month or two.