Hi Alicia,
I'm reasonably new to this too, but I'll share a couple of things I've learnt so far.
Don't get a telescope on an equatorial mount, they're too complicated for a five year old to manage. I'm still struggling with mine, and I'm 54.
A Dobsonian scope is much easier to use according to everything I've heard or read, or a telescope on an alt-azimuth mount, which works the same as a dobsonian except it sits on a tripod.
I've just looked at the Andrews site and there is a 6" Guan Sheng Dobsonian reflector for $299.
www.andrewscom.com.au/site-section-10.htm
Click on Guan Sheng and then Dobsonian.
I can't comment about the quality of this brand, but it's close to your price range. Someone else here might be able to give their opinion on this.
My reflector is a 5" and I can just make out faint bands on Jupiter, and can see the rings of Saturn but they're a little blurry.
I don't know where you live but the Astronomical society of Victoria has a junior section and the parents can go to meetings with the kids. They're located in Burwood.
www.asv.org.au
Click on 'Activity Sections' on the side menu and 'Juniors' is in the list that pops up.
I hope this helps, you'll probably get lots of better info from more cluey IIS members.