Roku is not capable of browsing the internet outside built in apps such as Youtube since it doesn’t have a web browser app. Trying to search the web without a keyboard and mouse is a pain and TVs don’t lend themselves well to show web content due to the large font sizes at low resolution. Use an iPad if you want to browse the web and stream content to the TV; most new smart TVs are capable of doing that, however your Sharp may be a little outdated for that.
Go to roku browser in apps. Why is it there and looking for a server on my network?