program application

Hello all, new to macbook pro, have an iphone 4S but just switched from Dell to Mac and the learning curve is kinda steep.
1. recently d/l CCcleaner (yah, I know overkill). How do I get rid of the icon on my screen please?
2. All email is collected on the MBP. When I send an email, the return address is my iCloud account. Would like my primary email as the return address and not ......@myicloud.com
3. Any good easy to understand icloud tutorials.

Thank you