You can download the near surface features explicitly (click "Single levels" radio button). Then select each variable that has "near surface" or "surface," in the name or is intuitively a surface property (such as sea level pressure).

For your own edification, pressure levels decrease with height. The 1000 hPa level corresponds with the ocean surface. This would be fine, but things like mountains, where the pressure can be significantly smaller, obscure the field.