If lucky forks are simply twisted in their respective clamps. If this seems likely then loosen top and bottom clamps, sqweeze front tire imobile between legs and twist handlebars left and right until alignment looks correct. If top tube have slid down in triple clamps during this they can now be re-clamped in preferred location. Tighten and test ride being carefully observant.
This assumes neither fork tubes nor handlebars were also bent.
Forks can be inspected by sighting along a straightedge held against one half of fork assembly and seeing if other half appears co-axial.
Bent handlebars tend to look and feel obviously wrong.
I bet you can diagnose and solve this yourself.