Selecting the right hook
Always use a hook size 1-2 sizes larger than the yarn band recommends. Using the same size as you would use for regular crochet or knitting will result in a fabric that is much too dense. For a fingering weight shawl, start with a hook between 4.5mm (US G-7) and 5.5mm (US I).
When investing in a hook set, choosing interchangable hooks allows for the most flexibility. There are now many options, Chiaogoo T-spin
is a quality affordable set.