Need MS-Excel advice on customizing cells and its formats

I’m a new user in Microsoft excel. I can’t properly use it I face some critical problem. If you send me the proper guidelines. It’s a great favor for me.
How I improve my skill in excel? I need some tips how to change cell formats.
How to select more than one column? Row? Or cell?
In Excel and how can I change the Column background?
One more thing, I especially said that when I include a phone number in a row the Microsoft excel sends me a message formula error.
How can I solved it. please send me the solution?
