Are you just learning how to crochet? Most crochet projects start out with the chain stitch. The chain is also used to move up to the next row or round in your work.
When reading a crochet pattern, the chain stitch may be abbreviated as “Ch.” For example your pattern may read:
To begin Ch. 30
And what that means is to chain 30. Easy enough right?
Now, to actually make the chain stitch start out with a slip knot on your hook. Yarn over (YO) and pull through the loop. Repeat this process until you have reached the amount that your pattern calls for.