Gaaelyin7Ajalon

Hope this doesn't sound too elementery but I'm not very social media or computer savvy! I downloaded the Second Life program which lets me get into the Knowledge Base and other tutorials including being able to post this question. But I can't access the SLURLs or destinations. When I click a Destination it says I need to "associate Second Life with a program" Do I need to download the Second Life Viewer separately from the initial Second Life program? I thought the Viewer would come with the Program - I just want to make sure before I download something that isn't necessary. But basically - I can't get past the Welcome Page. Thanks so much for any help you can give! Gaaelyin7