To add text to a Photoshop document, all you need to do is activate the Text tool and type what you'd like. Here are some instructions:
1) launch Photoshop 2) click File > New and choose a page size 3) press G to activate the Paint Bucket tool. If you get the Gradient Fill tool, simply press SHIFT+G until it changes to the Paint Bucket 4) change your background color to the one you'd like and click the Paint Bucket tool on your document NOTE: you've now got a document with the color background you'd like 5) press T to activate the Text tool. Change the font color to the shade desired by clicking on the color icon in the Options Bar 6) click in the document and then type whatever text you'd like, then click the checkbox in the Options Bar or the Enter key on the numeric keypad
There you go.
You might want to look into a class on Photoshop at your local community college or reading a do-it-yourself book. This is a really big and complex application!