How to set-up page with ‘fixed’ intro text

Hello,

I’m new to wordpress.

I have on this moment one page, two colums. At the top of the content I want to have a kind of intro text, this must always be visible at the main page. On the main, after the intro text starts the posts?
It seems to me that this must be possible but how?
On this moment I have put the ‘intro’ text in a post. But if I add a new post then the new one is at top. It seams to me that it is not a good idea (if it is possible) to change sort of the query to do the oldest post first or…
So:
Header intro text
bla bla bla etc.

—————–
First Posts start here

bla bla

—————-
Second post etc.
bla bla
—————

On every post people can give comments

Is that possible?

And it seems to me that this is possible, how do I organize this? Must I use categories? Or is that not necessary?

I hope that someone can help me

Thanks in advance,

Nico