No reason for a weight vest. No one would advise that.
I would say that there is more of a danger of messing yourself up with DL vs squat. This is a good video:
https://www.youtube.com/watch?v=4AObAU-EcYE
The older guy in it, Mark Rippetoe, wrote a great book that you should own, "Starting Strength." It's kind of a go-to book that everyone respects and cites.
Also a lot of good explanations with this guy:
https://www.youtube.com/user/athrall7/videos
If you are starting out the best advice I have is to NOT buy any anything beyond maybe gloves and protein. Just go to the gym, and for the first 3 weeks just lift comfortable weight and make sure your form is right and there is no bad pain after a workout. After that, just lift more so that you are lifting more for muscle gain and less for learning form(since you know it at this point).
Only after that should you get into pre-workout supplements. And thereafter lifting shoes, belts or any of this other stuff.