Sounds like you are downstream without a paddle, or a canoe for that matter. Here is what I would suggest doing instead:
1. Find Machinima sites that are current and looking for voice actors, editors, script writers/editors, etc. Find and read scripts. Go and watch the best Machinimas out there (Rise of the Spartans by Arbiter617 is one of the best). Doing this will make sure that you are part of the community and see how things run. You can see different ways of getting Machinimas off the ground, and those that are being made. Study the best ones.
2. Create ideas for Machinimas that are different (and I mean decently different) from others. Make sure your ideas are not too generic, or way too far out there so that it is impossible to do in Halo. Expand your best ideas into mock plotlines and create a few draft scripts fro certain scenes. Have the scenes sketched out, possible map locations (ie Adrift top blue Hallway), and have ideas of where the cameras would focus on. This is not your key to fame, but your key to getting involved in a larger Machinima or being a part of a Machinima team. Your need to show that your are creative and are able to visualize an overarching plot, and then work on the small details. But make those details count, they are what separates the good from the okay.
3. Now take a deep breath, because your work will get trashed on by others; I guarantee it. This is to be expected. Notice how I haven't told your to share your works yet, this is key.
4. You volunteer on projects, just helping out with small things at first (small voice role, background/minor body actor once you get live, minor script reviewer, etc). Show that you can do those well on a larger project, and you will get invited back for more things. After you find a good group, then you can start to share your ideas. You will of course have refined many of them, and generated more on your current project. If working with others, don't try to force or suggest too drastic of a change, unless you can list and explain your reasons for it.
5. As time goes on you can make a name for yourself and others you work with/for and make a decent if not top notch Machinima. Over time your will get Gold, get proper recording equipment, etc.
6. ?
7. Profit