I can't use my internet browser
Open your firewall or anti-virus software installed on your computer and check that your internet browser is allowed to connect to the internet.
Can you use your router's connection to access the internet?
It's important to find out if your router has an internet connection. If your router doesn't have an internet connection, you need to solve this problem first. When the problem is solved, you will most likely also be able to use your internet browser.