I think I can see your cold water handle in the pic, under and behind the top lines. It’s a black T handle that you pull up to open (not twist, like every other water valve). If the water hose above it gets in the way, you can turn the handle to position it so there’s clearance. Whatever you do, don’t remove the U shaped metal pin on the T handle stem- it can stay on when you open the valve and it’s a pain to get back on. Ask me how I know.