When a pattern starts with chains followed by any basic stitch, it is possible to combine these two steps to one, which becomes your foundation chain.
The advantage of this is not only a quicker start of your project, but the foundation chain is also stretchier than chains/stitches.
Below you will find a pictorial on how to do it with single crochet.
Foundation single crochet (FSC):
Begin with a slip knot and chain 2.
(These two chains do not count as stitches.)
Insert your hook in the second chain from hook – yarn over hook and pull back through the loop – you now have 2 loops on your hook .
Yarn over hook and pull through the first loop.
Yarn over hook and pull through both loops.
Push your hook through the bottom “V” of step 2 and repeat steps 2 and 3 till you have the required number of stitches.