By downloading and installing Apache, you are basically trying to set up a local server for development on your hard drive. This is not difficult, but for someone just starting out who does not really know much about servers and configuration . . . it may seem a bit complex for you.
At the same time, it is also far too much work for someone to type out step by step directions for you. There are so many things that can go wrong, it would take forever to try to give you all of the information needed. And also, we can not see what you are doing to help you.
Therefore, it is my opinion that it would be easier for you to find a really cheap host company that has a linux server with php and MySql support. These host companies are very easy to find, and some of them are super cheap.
It will be much easier for you to use your Dreamweaver and simply connect to your server and test/develop . . .then to install apache on your local drive, if you don't know what you are doing.
You can certainly test your luck and keep trying the Apache Install. It is, after all, FREE.
I work for a software development company, and we could probably offer you a small amount of space for a low monthly fee. (We have special development server packages especially for students!! ) But, I am not promoting our site, just letting you know that we can help.
There are tons of inexpensive server companies if you just search google.