I cant connect to my wifi i forgot my security key

Hello.

You just need to reset your router so you don't have to put any password anymore. To reset it, find the reset button, it is really small and you have to use a pin to be able to press it. Hold the reset button down for 10 seconds.

Depending on your router, it usually can be found here:

This leaves you with two options, either connect through a network cable then log into the router's web-based configuration page and get the security key from there, or, reset the router to its factory defaults (no security) via the reset button (you will lose all your previous configurations).

good luck