Things to know before 1st playthrough

Hi,

I never played New Vegas before, only Fallout 4. FO4 was good but I didn't like the story too much and the settlement system. I now want to give New Vegas a try (heard lots of good things) and I want to do a hardcore playthrough.

So my question is what thing should I know about before the first playthrough? I read somewhere that intelligence determines how many skill points you get etc. So how many point should I put into intelligence for example. I just don't want to sink in 20+ hours before realizing that my character is fubar.

Thank you for the input!

TLDR: What should I know about the game before my 1st hardcore playthrough? General advise and best practices so to say, no specific builds.