WizieCZ,
This forum can help you. Burt you must provide more derail.
Make and model of the router?
What kind of smartphone or computer do you have?
Many routers have the reset default details printed on a label underneath the router.
Example:
If your router is a D-link, it might be this model:
Here is the web site that explains how to get control of that model:
Resetting your D-Link DI-624 router to the factory settings If you have forgotten your router's user name or password, you must reset the router to the factory settings to access the configuration utility. You can't update any security settings unless you know the user name and password and can access the router's configuration utility.
Note: Resetting your D-Link router clears all of your home networking settings.
To reset your D-Link router:
With the power on (Power LED on front panel should be lit green), use the pointed end of a paper clip to press and hold the Reset button for 10 second
The above is from a service in the USA. In other countries the details might differ much. So,we need more detail about your router model number.
We want to help.