Do you find it difficult to play B Major? I certainly did when I first started playing guitar! It can be difficult forming a barre chord, so you may want to start with an easier version of B Major:
Once you've got this version down, try playing B Major using a barre chord. In order to do this, place your index finger across the first five strings on the second fret. Your middle, ring finger and pinky can all stay in the same position as seen in the video above.
As you improve with this B Major barre chord, try playing it along with the following chords:
C# Minor, D# Minor, E Major, F# Major, G# Minor and A#dim
You can mix these chords up in any order and they will all sound good together. That's because they are all part of the same key (or family). These chords come from the key of B.
Be patient and have fun experimenting with B Major!