Continue to do this for each vertical row. Once you have all rows joined vertically, you will start to join the squares horizontally, which is a bit easier since all the squares will be joined on two sides already.
I added a border consisting of HDCs around (making sure to put 3HDCs in each corner). I did 4 rows of Aran (cream color), 1 row of Forest Green, and 1 row of Chocolate Brown.
Click here to see the finished project.