With the Type tool selected in the Tools panel

With the Type tool selected in the Tools panel, click to add new placeholder text to the document. This placeholder text is called point type. With the placeholder text selected by default, type to replace it.
Select the Selection tool in the Tools panel. You will see a box around the text. This is called a text object. Drag a corner of the text object to change the size of the text inside.
Drag the text to reposition it.