The Evolution of Fruits
Fruit did not evolve from a single cell( except in the sense that plants did)  it evolved from seeds and their casing in angiosperms. Fruit is a means to disperse seeds. This will get you started on the different methods of seed dispersion. 
https://www.britannica.com/science/seed-plant-reproductive-part

By enclosing their seeds in material animals want to eat, plants get animals to transport their seeds long distances and deposit them in a warm pile of fertilizer. Sugar is the easiest macronutrient for plants to produce so that is the what they pack their fruit with. animals tend to eat new growth which often contains seeds so it is easy to see how animals with seeds tough enough to survive digestion (which many seeds do) would quickly spread. Any adaptation that made animals more likely to eat these parts and spread their seeds would likewise spread.

I suggest familiarizing yourself with basic plant phylogeny first, since if you had you would know only one group of plants produce fruit, and so would not have asked half your questions. So please go do a few minutes of research and come back with a more coherent question. 

If you want a complete retelling of the entirety of plant evolution you can do that yourself, show a little initiative and start here. 

http://bmcevolbiol.biomedcentral.com/articles/10.1186/1471-2148-14-23

https://www.accessscience.com/content/plant-phylogeny/524400

Also rice is not a fruit. It is the plant's seeds you are eating, it did not evolve to taste good, you evolved to think it tastes good becasue it is nutritious, in much the same way meat tastes good. You are essentially murdering their offspring. 

I also suggest learning what a theory is.