Amigurumi projects are usually worked in one continuous round or spiral of single crochet stitches, to create a typically oversized head, with a cute, quirky face, and undersized torso and limbs (which are usually crocheted separately and attached). It's often suggested that you use a crochet hook that's one size smaller than usually recommended for the yarn you've chosen in order to create a tight fabric (but an amigurumi pattern usually has anticipated this, so you should be fine following the specific instructions).
In stuffing your amigurumi creations, you might want to consider using a pellet-like stuffing rather than fiber to give it some heft and weight. In addition, whether you're using pellets or a fiberfill, you might want to use a clean knee high or cut pantyhose to provide a barrier between the fiberfill and the crochet so that the fiber doesn't start to peek out between the crochet over time.
Amigurumi projects can be a lot of fun, especially for beginners since only the single crochet stitch is used, and it's a great way to use up scrap yarns.