Gauge and hook size really aren’t relevant for this pattern. A smaller hook will result in a smaller truck, whereas a bigger hook will make for a bigger truck.

The trucks in the photos shown were made with sport weight yarn and a 3.5 mm (E) hook. I have also successfully made trucks with worsted weight yarn and a 4.0 mm (G) hook.

To successfully complete the truck pattern, you will need to be familiar with the following stitches:

CH chain stitch
SC single crochet
DC double crochet