You shall not make idols.
This second commandment is very close to the first one. The first one was talking about things in our life that may take the place or come before God. The second commandment is talking about making some more important than God. For an example, lets say one of your best friends invite you to hang out with them on a day that your family always goes to church. Going to hang out with your friends and ditching church would be making the idol. You would be making your time with your friends and idol.
I don't want to be too repetitive in repeating everything that I said in my last posts, but whenever we put God first, we will be blessed. God always honors those who put Him first.