To add text to your work, select Text tool, or the 'T' icon, in your tools window. With this selected, create a text box by clicking, holding and dragging.
Type what you wish into the box. Use the options bar to change font, size, colour or style.
When you are happy, select the tick which is also located in the options bar. You can always add more after the tick has been pressed.
If you wish to add shadow or glows to the text, right click on the layer in the layer window (below left) and select BLENDING OPTIONS... which will open a window. Here, select shadow and adjust the many shadow options to what suits you (below right). You can also play with the other options available, such as Bevel and Emboss and Outer Glow. Everything you do can be previewed as you adjust the settings and will not stay until you press OK.