You have to buy the full vocals from the sites that these samples were acquired from. I have countless other samples that I ripped from the "previews" of the full vocals and they are not original quality. Most of the samples just include a verse and chorus, which is perfect for throwing in a bhangra mix but hard to make a full scale production around one song.
If you're serious about production, holler at some local talent and get something recorded or simply pay the full price for the vocals. Some are actually fairly inexpensive because they're not as good

but they can be good for practice.
The best way to practice is to simply use the samples and make some sort of megamix with them. The focus as a practicing producer shouldn't necessarily be to have the best 'song' perse, but to improve production quality and improve technique. As you get better and better technically, and begin to get better material to work with, the product begins to take shape. If you can make something good out of something shitty, imagine what you can do with something good!