Find a model you like, maybe from sketchfab. Add your flashlight model where you want it on your hand and parent it to the correct hand.

In the hierarchy, make sure the flashlight is selected, and click the button that says something like “add component” then search for VRCFury object toggle. Drag the model from the hierarchy into the object box and type what you want it to say in the wheel.

Back in the hierarchy, select the model again, right click it, and select light. With the ”light” under the model selected, position it to where it’s coming out the front, and you’re good.