You've never done either, have you...?
Crochet stitches are a bit thicker than knit stitches, but if you use a little larger hook then they're not stiffer. They both use hundreds of stitch patterns which are just combinations of the basic stitches.
Knitting has really only one basic stitch - it looks like a knit on one side and a purl on the other and you work them a little differently depending on which side is facing you and what look you're going for. They can also be done on the same row in different sequences and if you do increases and decreases they will form different stitch patterns like lace or zig zaggy patterns. Crochet has several different stitches and they can be combined too to form different looks.
Look through the scarf patterns at www.knittingpatterncentral.com
to get some ideas what you can do with both types of yarn work.