Если у тебя есть велосипед, нарисуй его или наклей фотографию.

1) Being famous means being well-known by people.
2) The advantages of being famous are different. For example, people may follow your example, you can be like a "preceptor" for them. You can inspire people to do something that will totally change their lives. There are many cases when famous people could appeal to others not to make mistakes.
In case you're famous, you should know about the disadvantages. For instance, you may find many people who will envy you. Yet, they will be ready to do everything just to make you unhappy. It is a little bit dangerous to be famous, as someone can have an intention to kill you. Apart from that, people who are becoming famous sometimes forget about others. They become more selfish, more sassy and so on.