Help! I broke my wordpress blog…

Oh boy. Okay, I have my wordpress blog installed on my server, I’ve been making posts, and I was adding some cool stuff – only I broke it.
Hi all – technologically challenged newbie here. I think I broke my wordpress blog, and I’d appreciate any help (the step by step kind in language suitable for backwards four year olds, please)!

I’ve got wordpress installed on my…server(?)Website(?). I wanted to give it it’s own address – you know, where it says “your blog homepage to be different than the directory you installed wordpress in” – but when I clicked to the directions they lost me at #1 where it says “Create the new location for the core WordPress files to be stored (we will use /wordpress in our examples).”

I tried following the directions, but didn’t understand, so I put it back to how it originally was, but now when I write posts, I get error messages at the bottom of the page below the posts, and I have no clue how to fix it.

Thanks in advance for your help and advice!

Warmly,

Travel Writer