Hey everyone im a new member and just had a couple questions about my grand cherokee laredo 2003

I smell gas when im at a stand still with my heat on and from what i read theres possibly a leak. i do not smell it much when im driving so im assuming if there is a leak its not in the front of the engine but im not exactly sure.

any idea on where to start looking or anyone have a picture of the fuel system from a service manual so i have an idea where to look. Taking a quick look under and above the engine i dont see a liquid leak besides a tiny oil drop.

Thanks everyone