Your trip is nearly here! How great is that!
To get to"Ohana from the Animal Kingdom is quite simple since a bus will run directly from the park to the Polynesian resort. As you exit the Animal Kingdom, there is a sign indicating which number bus stop you will need to go to for each resort. You then just wander over to the Polynesian stop for the first available bus.
The parade is showing at 4:00 during your trip, so it is possible for you to see the parade since it is 15 minutes long, but you may be cutting it close because you may get caught up with a large crowd as many guests exit the park after the parade. If you decide to watch the parade, I would watch it from Harambe near the Tusker House/Dawa Bar area in Africa. You will be the first to see the parade and then can follow it out as it travels through the Animal Kingdom taking you right nearby the path that leads to the Oasis and exit. I would estimate that you would be exiting the park by 4:30, and the time to get to the Polynesian resort is about 15 minutes. What makes this tricky is if you have to wait for a bus to arrive or if it is crowded making you wait for a second bus.
Just this summer, we had a similar situation. We were trying to get from the Animal Kingdom to the Polynesian to change and head over to the Grand Floridian for dinner, but the wait for the bus was making things pretty close for us to get to our reservation on time. I called 407-WDW-DINE while in line and explained the situation; a cast member was able to bump our reservation time back so everything worked out well.