I would suggest you start with something like a shoebox. Most plant cells are rather square or rectangular in shape because of the support of the cell wall. The box will be the cell wall, and the rest of the cell will fit inside it. The wall should be lined with something to represent the cell membrane - plastic wrap or a plastic bag would be good. Inside that, you need to include a nucleus, which should be some round object, and mitochondria and chloroplasts, which should be shaped like a kidney bean - they can be the same type of object, but the chloroplast would be colored green and the mitochondria some other color. The Golgi apparatus resembles a stack of pancakes or a stack of baggies. The endoplasmic reticulum is also a series of folded membranes; smooth ER is plain, but rough ER is studded with ribosomes, which would be tiny bumps. You also need a good sized inflated plastic bag or balloon in there to represent the vacuole. Those are your main parts; there's a photo of a great plant cell model at this link, which might help get your creative juices going.
thanks a lot. your answer will help a lot