What is how to start a crochet chain?

Here's how to start a crochet chain:

The Chain Stitch (ch) is the foundation for many crochet projects. It's a series of interconnected loops that create a flexible "chain" of yarn.

Make a Slip Knot: This is your starting loop. Wrap the yarn around your finger, then loop the working yarn (the yarn coming from the skein) over the loop. Pull the working yarn through the loop on your finger to create a new loop. Slide the loop onto your crochet hook and gently tighten it. This is the slip knot, and it does not count as the first chain.
Yarn Over: Hold the hook in your dominant hand. With your non-dominant hand, bring the yarn over the hook from back to front. This is called a "yarn over" (YO).
Pull Through: Use the hook to pull the yarn over (YO) through the loop already on the hook. This creates a new loop on the hook, and you've completed your first chain stitch.
Repeat: Repeat steps 2 and 3 to create the desired number of chain stitches for your project. Each time you yarn over and pull through, you create another link in the chain.

Tips for Success:

Tension: Maintain even tension while creating the chain. If your chain is too tight, it will be difficult to work into. If it's too loose, your project will be floppy. Practice to find the right balance.
Counting: Be careful when counting your chain stitches, especially when starting. It's easy to miscount. Use stitch markers, if helpful, to mark every 10 or 20 stitches.
Consistent Size: Aim for a consistent size in your loops. This creates an even foundation for your project.