Icons on Illustrator

[#1]

I recently started using Illustrator, I'd like to know if there are icons (such as phone icon, or mail icon etc.) that could be used or else, if someone could get me a website where I can download some of them. 

[#2]

I recently started using Illustrator, I'd like to know if there are icons (such as phone icon, or mail icon etc.) that could be used or else, if someone could get me a website where I can download some of them. 

[#3]

Open up the Symbols panel (Window > Symbols).

In the panel menu, go to Open Symbol Library and choose one of the libraries there. 'Web Icons' or 'Mobile' contain the examples you gave.

There are many more online. Just google 'Illustrator Symbol Library'.