§ 1. Open an image to your choice.

§ 2. In the Toolbox, select the Horizontal Type Tool.

§ 3. In the Options bar, define font style, size, color, and other options.

§ 4. Click there, where you want to add inscription and type some text.

§ 5. When ready, press [Ctrl+Enter] keys, or click the "ok" button in the Options bar to apply the typing and return to normal editing*.
*Most commands won't work until you exit the "type" mode.

§ 6. To edit the created text, select a fragment with the Type Tool. Then change the text content, font, color, position, etc. When finished, apply your changes [Ctrl+Enter].

NB Although working with the Type Tool feels very much like using a regular text editor, for efficient work with text you have to understand layers.