Don't get hung up on the label "beginner".
You ARE a beginner. Your backhand is working from scratch.
Most of the guys here giving advice have been playing tennis for over 20 years, some closer to 30.
And using Federer as an example is about the worst thing you can do. He talented, no one else anywhere is.
Like you want to play basketball, and use KevinDurant as your example to copy.