Should I babysit a developer? I spent 12 hours trying to help a guy set up his development environment, and this guy had 10 years of experience somehow. He was supposed to be at least intermediate level I was told by my manager, and he asked me how to do a pull request using git, which is a very basic thing every developer should know. So I told him to google it, does it make sense? I was also asked to google things that are much more advanced and I managed it on my own. I am a developer with almost 5 years of experience and I became senior recently, so I am just asking if what I did was reasonable. The guy seemed to have lied through his interview process, because he doesn't know how to do the most basic things and seems to be completely clueless.
To answer you question: you shouldn't "babysit" him, but do provide some coaching and guidance. There are developers who have never used (or barely used) Git or the Linux command line. Provide him with resources to help him learn the job requirements. For example Codecademy provides some free courses on common tools; they have a course on Git and one on the Linux Command-Line. Another option is to provide him with a subscription to Pluralsight or other e-learning platforms.
Are for how to politely tell your co-worker to "Just Google it," see How to politely ask a coworker to “Google it”.
Well, you tell us.
When they said 10 years experience, did they say 10 years experience with git?
When they said 10 years experience, did they say 10 years experience with linux?
If they did, then I understand your anger.
On the other hand side, your post reads as if you took your 5 years of experience and expect everybody else to have the exact same knowledge. You seem to not comprehend how vast the field of programming is. If you have 5 years experience, you probably weren't born when I started. I have programmed in languages and used version control systems that you have never heard of. I can use them in my sleep and the were absolute standard 10 or 20 years ago. Does that make you a bad developer? Does that mean you should be fired? No. It just means there is so much to know about software development out there, you will rarely meet anybody with exactly the same experiences you have.
Maybe you should take it as something good. If he actually knew exactly what you know, just more of it, why would the company still need you? Be happy that you can probably learn a thing or two about things you don't know. Because if they could use the linux command line and do git pulls, there would be nothing for you to learn from them. Instead they probably know other cool stuff that you can profit from once they explain it to you.
Making a pull request is a bit different on different repository hosting service. There is Github, Gitlab, Azure DevOps, AWS CodeCommit, SourceForge, BitBucket and so on. I have few years of experience with Git but if my company decided to start using AWS CodeCommit for repository hosting then I would need to do some research.