Layman terms:

Laminated is compressed wood fibre + paper

SPC is stone & plastic mix + paper

vinyl is plastic + paper

Engineered is 1 layer nice looking / expensive type of wood + multiple layer of cheaper wood / plywood

Solid wood is 1 whole thing real wood. So the nicer looking / expensive species = very expensive

First of all, your base must be flat enough and 1mm pe foam or 1mm Eva rubber underlay are good enough. Depend on your site situation too.
Not really, can be solid wood, spc or laminate. Depend what the developers gave tho.