I need to find some good examples or quotations in that book that shows Piggy being made fun of, having useful ideas, advice and how is he used by Golding to advance in the next novels?

Hi, ergindavid!

Have you tried the following search?

Lord of the Flies Synopsis Piggy Golding - Google Search

If you click on the link and read and study information that you'll find on other sites, I'll bet you'll be able to come up with some of the ideas after which you seek.

Also, if you click on the following link, you should also be able to find additional information that will be helpful to you.

Lord of the Flies - Wikipedia, the free encyclopedia

Thanks!