For a possible career path, I would likely need a portfolio of nonfiction writing when applying for jobs. So I have several things I would ask of you.
First, where is a good place to store writing online? It would be preferable if it had it's own text program built in because I can not stand using Microsoft Word and I always type much faster and more elegantly outside of it. However, I don't really want to start a blog either, as I don't want just anyone coming along and reading it. I am too private a person for that. I wouldn't mind a community that would be supportive and helpful in improving my writing if such a website exists.
Secondly, what would you want to read? If you give me some ideas, I could write something for you. I am also good at research, so if there is something you are curious, send that my way as well, so I can write a report on it. Just don't expect you can turn it in to your professor as your own work. :P

I'm not sure about where to post or store writing online, but as for you second question I think you should write about something your passionate about. c:
I wish I could say more but sometimes less is more, no?
No, that's not really helpful. I'm passionate about way too many things. Ha ha...

Oh, I see...
Well, sorry I couldn't be of more help.
I personally use Google Documents for everything. I've found that it is a good place to write and store writing. Otherwise I use other writing tools like AlphaSmart and upload documents to the computer at a later time.
As for getting started with nonfiction writing, I would make a list of your interests and see if any associated online communities are accepting articles/intern writers. Not only will you gain valuable experience, but you will also have a chance to receive great feedback from community members. Another bonus is that some of these communities are looking for specific prompts to be filled so if you're stuck on what to write you will have a little something to help you get started.
I can't help with what to write, but to store my writing I use Simplenote. There's an app for iOS (not sure about android) and a website, so I like to use it to write from my phone or my computer and have it all synced together. You can also add tags to your writing which is useful if you have a lot of notes. However, it doesn't let you change the style of the typing, so you can only use the preset font and type size. :( As Pilgrim suggested, Google Docs works very well too. It's a lot better with actually editing the text. It's like a way better (and free!) version of Microsoft Word.