If the text is in a table cell, you need to click the cell before you can select the text.
Select one or more characters: Click in front of the first character, then drag across the characters you want.
Select a word: Double-click the word.
Select a paragraph: Triple-click in the paragraph.
Select a range of text: Click in front of the first character, then hold down the Shift key on your keyboard and click at the end of the text you want to select.