I just started playing Civilization but it's complicated and I need a guide?

[No-man-s Land]

I'm playing Civilization 4. I love the idea of growing up a civilization throughout times and I've tinkered around with it a little bit, but I have absolutely no idea what I'm doing or what my goals should be. I tried looking at a few videos on YouTube but they seem geared towards more intermediate players than someone like me who doesn't have a clue what the first thing he should be doing is.

Can anyone offer a guide or just give some simple tips about what I should be trying to do?