Works at any fret , say 3 (G Major)

E --3--
B --3--
G --34
D --3-5
A --3-5
E --3---

You might notice that this is an E chord shape

Proper way- hold finger nearest thumb across all strings at fret3 (daunting isn't it- i remember), put next finger at fret 4 on 3rd string, put finger 3 at fret 5 on 5th string, put your little finger at fret 5 on string 4.

Cheat- only hold down the first 2 strings with your first finger!!

Please note that i'm not brilliant at barre chords and with have been known to **** them up.

Finally .Practise,Practise,Practise or Practice,Practice,Practice - as we say over here. Try only playing barres for a short while and then go back to "ordinary chords" ,or easy to hold bits, or you will knacker your hands.

Good luck and keep,um,on keeping on.