For a nontechnical person, you've already accomplished a lot....
However, the laptop that you bought - did it come with pre-installed Security software? If so, disable *that* and allow your laptop to connect to the router for the first time. Then, with the connection active, re-enable the security software so that it can allow that connection to go through.
Sorry cannot provide more details, but until we know *what* security software came with your laptop (McAfee, Norton, etc) we can;t tell you how to disable it.