i need help with my router, i have no idea what to do, NOO idea, it is wayyyy to hard to figer out.

when i try to take a test for school online i can not enter the website, when i try to play viedo games online it says i have a stict firewall and i can not play, and the range of my router isnt as far as you people say it should go.

so i need help with all this.

someone please help