can anyone tell me how to make my own whenever i try it within a day the air has got to it and it turns green iv tried putting a layer of oil over the top but that doesn't work do i need to use a bit of white vinegar?

The best method for keeping most things fresh is to freeze them.
Make your garlic/ginger paste and then place one portion or the amount you most generally use, in an ice cube tray and freeze.
When you want your garlic paste just take it out the freezer half an hour before use.
You'll be surprised how far you can get a lump of ginger to go, and you never have to throw away that piece thats always kicking around the bottom of the fridge.
Also by freezing you dont add anything to it that would alter the taste of it, ie vinegar.

You should do what the BIR's do
Blend the garlic and ginger with the oil
You can also add a little water and salt, but that's not necessary
Keep it in a sealed container in the fridge
I use mine a month after I made it, with no ill effects
And it won't turn bluey green
I use a full bulb of garlic ,a similar volume of ginger, 2 tablespoons of veg oil, 2 tablespoons water and half a teaspoon of salt
If I'm making a larger quantity, then I don't bother with the salt and water

Try Panpot's Ashoka Garlic Ginger paste recipe

Hi

Here we go again, try using mustard oil.

50/50 garlic and ginger in the blender with enough veg (not mustard) oil to make a fine paste and a little salt.

Quickly fry the paste in mustard oil, with 1 or 2 tsp of brown sugar, until just fragrant. Keeps covered in the fridge for ages.

Cheers
CoR