You've actually asked about eight questions there. But here is a quick run down of what you need to do.
First, get the pictures to your computer. Either e-mail them to yourself, or plug your phone, or the memory card from your phone into your computer. Which ever way you need to do it, they need to be on your computer.
Second, make a copy of all of your image files in a second folder. Call it "working" or something like that. NEVER EVER EVER edit your original! NEVER! Edit a copy.
Next open photo shop. Then open the image using File>Open>(select your image file)>Ok.
If you have not changed your default settings, you have a bunch of icons to your left. One of them looks like the letter "T". Click on it to select your "Text tool". Next click somewhere on your image, or click and drag to make a box, that your text will go into. Type what you have to say and click the check mark up at the top, right side on your top menu bar. Select your "Selector tool" that looks like a mouse pointer located on the left at the top, above the "T" icon. Move the text to where you want it. And there you are. Save it as a PSD file (so you can remove/edit the text later if you like). Then "Save As" whatever file you are going to use (gif, jpg, etc).
I would recommend that you create a "Layer" to do the text in. By doing this, it is like putting a clear sheet over the image and writing on that. You don't actually change the image this way. The layer can be turned off so the text disappears if you want.
Create a new layer by: Layer>New>Layer, or Shift+Ctrl+N.
Go to photo shop essentials dot com. Get the basics down. They have some really good tutorials. They are easy to follow and don't overload you with things you don't understand.
Once you get the hang of it you can do all kinds of things with your images. You can create text that is transparent and blurs the image a little. Looks like the letters are made of glass.You can remove "Red eye", adjust the colors and much more.