Safety first but if you are going to see if you can do it yourself you can slacken off the front axle bolt (the one that goes through the wheel ) and the bolts holding the yolk to the forks (often 2 bolts per side - upper and lower). Then just tighten them up again to the correct torque. When you slacken them you need to be careful as if the weight is on the forks then there is a chance of the forks sliding up the yolks and causing damage. Best done if the bike is being supported by a jack with the front wheel just on the ground.
You could also have knocked the front wheel out of shape. Jack the front of the bike up and, looking from the front, spin the front wheel to see if it is wonky.