lost my iphone and cant remember my apple id password

See -- If you forgot your Apple ID - Apple Support.

If your iPhone, iPad, or iPod touch is lost or stolen - Apple Support

I would also recommend calling your service provider. they usually (in north Americas) have a way of blacklisting your IMEI number so it cannot be used by people who find it by swapping SIM cards.

if your provider asks for your IMEI number you should be able to find it on the back of the iPhone boxes on a sticker usually located at the bottom left corner.

(most providers already have your devices IMEI number).