Counting your crochet chain.
Most crochet projects start with a chain. It can be confusing when counting a chain length, so it helps to know where your chain length starts and where it ends. Take a look at the two photos. The photo below shows the right side of your crochet chain, it looks like a plait of 'v's. Every 'v' counts as a chain stitch. When you have finished working your length of chain, the slipknot is counted as the first chain stitch but the loop on the hook is not counted, this loop is called the working loop.
The photo below shows the back of the crochet chain. It looks like a line of arches with a vertical bump or hump in the middle linking them together. Some crochet patterns may tell you to work into this back bump/hump of the chain.
Now see How to keep your Granny square straight HERE
And How to crochet a straight Border HERE