The core components of cells are the outer membrane, the cytoplasm (substance inside which contains all other stuff) and the nucleus (contains DNA). All the other stuff is made up of various components with specific functions – these are called organelles.
The ones you must know about are:
4. Chloroplasts (plants and algae)
5. Golgi apparatus and Golgi vesicles
8. Rough endoplasmic reticulum and smooth endoplasmic reticulum
9. Cell wall and plasmodesmata (plants, algae, fungi)