Restoring locked iPhone without internet or iTunes

Hello, I come here truly desperate.

Recently I found my old iPhone 4 and hoped to give it to my sister to use. However, I am unable to remember the password that I’ve set.

After reading multiple forums and guidelines I discovered that when I connect it to any computer the only information showing is “the USB is unknown and/or broken” thus its not recognized as an iPhone so it doesn’t connect to iTunes so it can be erased (the cable i’m using works fine as it charges it so its not broken).

What is more, since using it my wifi password was changed, so its not connecting to the internet, therefore iCloud doesn’t detect it making it unable to erase( “it will be erased after connecting to the internet”.

Is there really nothing that can be done?

Its unbelievably frustrating when it works perfectly fine but can’t be unlocked in any way as its not recognized by computers and its unable to connect to the internet.

Its extremely important to me and if anything else can be done I wish to know it.