I can't speak for the Capstone course in Psychology, only Business (MGT 499), but remember a lot of your grade should not come down to the final paper. Here's the syllabus for the course:
PSY 499 Syllabus
40% of your grade is from discussions, 21% from 3 drafts, 4% for your proposal, and 35% for the final capstone project. You have 2 months to do it, and let's say you don't really get into it until the second month. So you have 4 weeks to write about 7.5 pages a week. For the 3 drafts, you'll get 7% points for each. (10 pages you have to write for the first one, the next 8 pages for second one, and next 7 pages for the third draft)
Let's say hypothetically you only did discussions (40%), 4% of your proposal, you only wrote all 25 pages (21%). That means that before the final, you'll have completed 65%. To get at least a C in the course (if you're having that much trouble), you need a 73% in the class. 73% - 65% = 8%. If all you got was a 8%/35% = or a 23% on the final paper, you'd still get credit. Even if you didn't get full credit for the other stuff, you'd probably need between 23 - 50% on the paper to pass the class.
How's that for perspective

Of course, you'd need to make sure you do well on the discussions, and 4% for the proposal, and your drafts to get the 65% or as close as possible to it.
The drafts force you to write a certain number of pages by each deadline so it keeps you on topic. Another way to look at it is that you're writing 15 pages single spaced, not really 30 pages.
Finally, pick a topic that is easy, interesting, and has a lot of stuff to talk about. I dislike it greatly when instructors or schools have mandatory minimum page requirements for papers. Some papers don't need to be 30 pages, and you have to write fluff or rehash the same ideas. Quality coursework cares more about the ideas and thoughts more than the word count. There are also tricks you can do to extend the length of a paper if you are getting close to the page limit. I find that sometimes I'd be only a few lines or half a paragraph away from the page limit, so there are some formatting tricks you can do to extend the paper

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http://www.instructables.com/id/How-to-M...r-longer./ The longer the paper, the more pronounced the effect is

With a 29 page paper, you can generally extend it by a page or two through some formatting tricks.
This is an undergraduate course, and the grading standards should be a little lax considering it's not a school known for being academically super rigorous. Try to find out what the professor's name is before enrolling in it - i.e. do a ratemyprofessors.com search for that person and see what people have to say about that instructor. Keep in mind the professor may not pop up through charter oak's list but through another college because Charter Oak contracts with other school's faculties who want to make some extra money on the side. A lot of the topics you can write about have already been written about, so you should have some skeletal structure you can compare to. I'm not advocating paraphrasing or plagiarizing mind you, I'm just stating that you can derive your own ideas from google searches, articles, papers, etc that others have written to synthesize your own ideas.
At least at the undergraduate level, instructors know that a lot of work is not original, and mainly derivative (i.e. a review paper), just focus on finding a topic that is interesting for you, and which you think you can write a lot about. One way to know that is by doing lots of google searches and seeing if you can find a lot of content you can use before committing to it.