Yes, you would need software - and time - to process your images from RAW. I believe Pentax still includes a disk with a basic program that you can use (could be wrong about that as I have used other software for years.) When you shoot RAW, you do not have any images, just the raw data. Your computer will not even recognize the files as images. You can get a lot more control over image adjustments, colors, exposures, white balance and so on but it takes an effort to process each image. There is a learning curve.
In your case, I'd counsel you to forget about RAW for now and use JPG, or shoot in RAW+JPEG mode so you will have jpegs to give your friend and also have the RAW versions of your images to learn with. Your camera will take and save both if you select that option in the main menu. I think you would be better off shooting the best JPGs you can until you know a bit more about RAW and the processing that goes with it.
On another note, if you want to include the trees and such in the background of your images as you indicate above, then forget about setting the aperture for shallow depth of field and shoot at f11 or so. Try both, f2 - f4 to blur the background and f11 or f16 to sharpen it.