Do great white sharks like warm water or cold water?

Both.

Though they are more often found in cool water rather than very cold [e.g. South Africa and Australian south coasts and often around seal colonies, where they mate and pup.

They are however avid travellers and are not uncommon in warm waters, even equatorial seas [but usually deeper there].

I have personally seen a few in sub-tropical waters and very large ones have been caught off Kenya.