@Ana1234 - Most routers and network switches and pretty much anything electronic these days will have a manual available online if you look it up. Even if that doesn't help, you can search online for a solution to your problem. There are so many websites where people volunteer their time to help out others and they are good at explaining the solution to a problem with simple terms.
If you find one online you will even be able to interact and search for the solution together. However, the other option is to buy a new router. They aren't that expensive and getting a new one means that it will have a warranty as well, which you might find useful one day.