Can you help me?!

HI - I would love to answer your questions - however as you note they have been asked hundreds if not thousands of times -

Just use the search function available and you will get your answers

All you need is traffic.
If you have a website which gets good traffic you can advertise other peoples services and get a commision when someone buys that other product.
The key is traffic.

In fact, there are varieties of ways to make money online.
Just like you say, if you want to make money from advertisement.
First, you need a website/blog. If you don't know how to do the programming to set up a website, there are many blog services online that help you easily set up your own blog by simple clicks. Like blogger.com

Just like the advertisement on TV, if few people watch the channel, then nobody wants to put advertisement on it - Just a waste of money. So you need website traffic - visitors.

Find a niche that you are interested or good at, write some original content and add to the website/blog, promote your website/blog in your Facebook/Twitter/Myspace, or other relevant forums. If your website/blog has considerable traffic, you can consider to put advertisement on it. Like Google Adsense, and banner ads from buysellads.com

You should now, no matter you want to make money from advertisement or affiliate marketing, you should know content and traffic are very, very IMPORTANT.

It seems that you are really new to this field, there are many other essential things you should know. Go on and learn from your friends and forums.

Good luck.

On internet there are a lot of freebies you can get in order to help you make money online. My experience was to start by reading hundred of internet marketing ebook (select the best niche that you prefer like IT, Online Advertisment...something like that). After several months of reading and learning, you will understand more clearly about how the online adsversisment works.

Hope that helps!