Selecting data in dataGrid (WPF)

Hi guys,

I am new to WPF so any explanation would be appreciated. I want to do a simple thing, but can't find appropriate solution.

I have dataGrid that displaying some data (cust ID, name, lastname, city etc). Next to it I have few textboxes (empty). I want to fill textboxes with cell value from selected row. So, when I select second row then in first textbox should be cust name, in second tb cust last name etc. That is first problem, and second is that I can't select row in datagrid by just clicking on some cell, instead I must click in small field in frond of every row. Is there any chance that this can be changed? I know that first problem have solution and that it is possible very simple, but it is big problem for me. I tried to use SelectedCellsChanged or SelectionChanged but I can't get value from selected row.