Like others have said, it depends on what you want to do. I’ve gotten to venues for bigger bands an hour before showtime or just as doors opened and had a view I was happy with every single time. If the priority is to see the screen and just take things in, then I think you’d be okay there too. Unless you wanted a specific rail spot, there’s really no reason to line up earlier… unless you wanted, say, a place to lean on or that sort of thing. Meeting up with fans is fun too though and can be part of the experience either way you do it.