Having massive issues with network

first i plugged everything in, but one of the two comps wasnt running off of the router, called our isp and they reset the modem enabling the other comp to run but now, basically stayed up al night trying things like manually inputting the ip address mask gateway n dns servers but all it did was say it connected and not pull up anything related to the internet when i attempted to do so, so im here asking for help ive no idea how i can fix this and idk if it s a router issue or the computer's