Hi There and Welcome to GDS
At first I wondered too about using templates.
I tried them out when I first started scrapping and found them to be a lot of work. But when I tried to do things by myself, I had such trouble with placement and sizing and making a page that looked put together. So I gave templates another shot. Using them really helped me to learn my program because I had to learn things about layering elements, clipping your photo or papers to the template pieces, and resizing. For me it was a great tool to get a page done that looked pretty, I got to play around with different papers and elements with ease, and I learned my program
I am not sure what program you use for scrapping. (I use Photoshop) Most templates that you buy will usually come with a layered file in a .psd format and the individual .png files for people whose software doesn't use .psd files.
Since I use Photoshop I tend to use the .psd layered file. It is quite easy to move the layers around, size elements, change direction and more. If you use .png files, you would just drag each .png file onto your workspace and arrange them.
There is great flexibility in templates. You can use the template as is, and just clip in or layer your own papers and elements. Or you can rotate the template, rotate certain elements and move things around to fit your photos. You can also use templates as a jumping off point -- maybe you have a template that has a fe photo frames and flowers scattered about. You might really want to do a boy page and have no need for flowers. You can replace those flowers with stars or buttons or bugs or whatever and place them where the flowers in the template are. The possibilites are limitless.