HELP

I don’t know if this is the right forum but I will give it a try. I bought a bike yesterday for fun, mostly to get around. My first ride felt a bit wobbly when I realized that the handlebars are set just half a centimeter wrong from the wheel and I now try to adjust the handlebar without any luck. I have loosened all the nuts without success and next step is to lubricate it but where??? What is it I should turn to get the handlebar to loosen??