Can you use Canon lenses to Nikon Bodies?

Can you change the mount of of Canon lenses to Nikon mounts in order to fit?

No. That's why you have to take a look at what each maker Canon & Nikon offer in the way of lenses and their prices. I don't use either being a Pentax man these days, so can't comment on their price structure. And no you do not want to try and mount a Canon lens on a Nikon body, For one thing the electronics are different and for another if you could you would most likely be taking a fully automatic lens and be forced to use it in a manual setting mode. Which would mean after the exposure was ascertained, you would have to stop and set the lens accordingly=a real pain!

So your decision is cast in stone: Canon or Nikon and their lenses or companies like Sigma & Tamron who make lenses for both of these cameras.

Yes there's something called a lens adapter search for the specific lens adapter online or got to camera store with an experienced staff. The only problem is the autofocus won't work this is ok if you shoot manually. But it is just not gonna be the same

You can, with the right adaptor, use Nikon lenses on Canon bodies. But, to quote Ken Rockwell, "Canon cameras have a shorter distance between the lens flange and film plane than Nikon." This means a Canon lens on a Nikon body would be bring the elements too far apart for true focus. You'd loose infinity and probably only be able to use it for macro or closeup work.