OK, I admit it. I'd never even heard of OneCloud until I read your question, so my answer is based upon a bit of googling which i
hope will help (but I'm giving no guarantees!):
I found this:
"Users can access their Box.com accounts through a variety of mobile apps, including Box for iPhone and iPad, while access via desktop or laptop must be done through a web browser, with drag-and-drop file support limited to Firefox and Chrome."
That suggests that you can access your account (and download files from it) from your home computer (using either Firefox or Chrome). After rather more googling than I anticipated I'd need, it seems that this is the login page you require:
https://app.box.com/login/
Alternatively you can access your account from any device and send a 'share' link to your own email address (for a single file or for an entire folder) and then use that (from your home computer) to download your files.
The format your documents will be in will depend upon which format you saved them in (which might, in turn, depend upon which app you used to create them). However most word processor apps will save into Word format (or something that can be opened by Word) by default. So you probably won't need to do any file conversion.