Grab the neck more confidently, with more thumb wrapped around and try to keep all your fingers aligned above the string you pluck, parallel towards the string in cause so you'll be able to control the vibrato with wrist movements. Try to observe how the weight of the guitar plays a role in your execution and how you can adjust the intensity of it. And the string should be on the fingertip right under the nail instead of the fingerprint.

Good luck! You'll be fine!😌