Here's my very first attempt at adding texture to a photo. It took me a while, and I still have a lot to learn, but I think my first textured photo came out pretty good. I used GIMP. It's a free software you can download from the internet.
Special thanks go to Kim Klassen Cafe for informing me of this software, Muddy Boot Dreams for the free textures, and the YouTube GIMP Tutorials to get me started with the basics.