There are three organelles (at basic high school level, that is) that are found in plant cells that are not found in animal cells.
The Chloroplasts: These contain chlorophyll, a green pigment that is needed for photosynthesis.
The Vacuole: This acts as a storage unit, containing minerals and nutrients needed for the plant. (At high school level, though at higher level you learn slightly differently.)
The Cell Wall: This provides structure and support to the plant cell.
I hope this helps.