Help with camera/lens upgrade *beginner

[Autumnbeattie]

Right now I have a Nikon D50 that I got used a few years ago just to take pictures of family things. I have enjoyed taking pictures and would like to upgade and take some classes. Mostly I would like to photograph children but I also have horses and would like pics of the kids riding. I was thinking later to learn wedding photography. Advise on a camera that could help with all would be great. Im open to Nikon or Canon.
right now Im looking to spend $2000 or less

 

[czarben]

I recently bought a Nikon D3200 and am very happy with it. It is easy to start using, but still has a lot of potential even as you gain more experience. Here's a little slideshow I made from pictures I took with my D3200 so you can get a feel for the quality.

 

[iolair]

Which lens(es) do you already have for your Nikon?