I'm new to AF, as new as someone can be.
I've got a problem with my timeline. My timelime is down the bottom from the left of the screen all the way to the right of the screen, which is where I want it to be, however, the part where u do all you're keyframing etc, is on the right hand size, and is really small, there is know way you could do anything in there due to the box being so small.
I've tried to go back to default setting to try and fix it, but It still doesnt fix it.
When I watch video on AF on utube, there "keyframing" box takes up half the screen at the bottom.
How can I resize this?
Without a screenshot, I can only guess what you're seeing and referring to, but here are a couple of pages with information about configuring the user interface:
columns (so that you can show or hide columns to manage space)
workspaces and panels (for resizing panels and choosing panel layouts)
Start here to learn After Effects: http://adobe.ly/bjBT3P
What Mr. Kopriva suggested. Read up on how to re-arrange and show/ hide columns in the timeline as well as AE's workspaces.