Sandbox

I have installed and set up Joomla, and have been playing around with it, but am really unsure where to go from here. I have a lot of ideas, but need some guidance. I guess my question is, is it worth giving it a try myself or should I hire someone? Where should I start? Here are my ideas:

Users will be able to:

Create their own blog, search through other blogs, comment, rate
Get points for participation (ie posting a blog gets certain amount of points, posting a comment gets certain amount of points, posting on the forum get certain amount of points)
Submit articles for publication
Submit terms to a list
Create their own Myspace/Facebook-like profile
Connect with other users
Start and join groups
Chat with other users through site instant messenger
Upload photos and videos
Post to the forum
Submit content (photos/videos) for contests - voting system
Post to classifieds section for small fee

Other general website ideas:

Wikipedia-like database where topics can be submitted and then edited by other users
User's ability to search for nearest location of particular type of park, store, etc, and allow users to submit their park, store, etc.
Guestbook
Rotating banner ads (both horizontal and vertical) throughout site as well as in blog/forum areas
Link database where users can submit their link and view other links
Event calendar where users can search for events by location, type of event, etc. Also allow others to submit their event.

I appreciate any help you have to offer.

There are a whole assortment of modules and plug-ins that extend the functionality of Joomla. Here's a good place to look:
http://extensions.joomla.org/

A lot of what you would be looking for is there.

This really isn't a specific coding question. Are you a programer, or considering?