What do i need to do to make my nikon D5000 take old school/style photography?

I have a nikonD5000 and am trying to give it that old school look.perhaps from the 70s or whatever. Not quite sepia sort of that old italy touch f you will. Any other tips will help imm trying to really express and find what i wanna do with my phtography.

Photoshop. I really doubt you can make a modern digital camera have that 'old' look naturally in camera. Sepia is probably the closest thing you can get to it.

What i do is turn my ISO high… To about 1600.It gives almost a pixelated view to the image.
probably not the best way to do it, but it has worked for me.

You could use the black and white or sepia color profile, but the best thing you can do is use RAW (NEF) capture and then open your images in Photoshop and take it from there. The camera is very limited in what it can do in this area, but Photoshop is virtually unlimited. With RAW capture, you will have the most data to work with and you will be able to do whatever you want.

Pictures in the 70's looked just like pictures today. SOME pictures from the 70's have faded and maybe that's the look you are trying to achieve. Just desaturate until you like what you see.

If you insist on doing this in the camera, you can reduce the saturation on your custom shooting menu.

You need to learn how to use your camera first--the photo that needs to be edited needs to be properly exposed, and focused.

Then you use Photoshop or Lightroom do edit them, like this.

There are film emulation filters/plug ins. The grain and colour characteristics of various classic films can be applied to your image. Play around with de saturation. A lot of digital photography can look too clean.
Classic black and white film of the 70's period would've been Kodak Tri X favoured by photo journo's. Punchy, contrasty with a fairly coarse grain that gave a gritty feel.

Try adobe photoshop or aperture