what thickness wayrock do i need to use.
First mistake is don’t use chip flooring, its total crap but an absolute minimum would be 18mm but for a little extra you can get a "proper" floor. I wouldn’t go anywhere near chip, especially for a bathroom or kitchen & if you tile, it will most likely end in disaster!
Does it need to glued together.
Some do, some don’t but it won’t make an awful mot of dereference; the end result is it will still be a crap floor!
Use a better flooring material; either T&G timber or, if your tiling that bathroom/kitchen, WBP ply. The thickness you need will depend on your floor joist/size/pitch between 18-25mm.