ILS Approach HELP!!!!

O.K I have all the settings "Autopilot on" correct flying steady on course (Boeing 747). Altitude, speed O.K. now we come to the landing. Fine via VFR just about.!!
However with the IFR rules the last command comes "Turn left heading ...etc then expect vectors for the ILS approach/runway. I cannot whatever I seem to do intercept this I see no visual or audio confirmation. tried "Approach Hold" Button.
Generally, just fly right by.....So frustrating. I just can't get into the glideslope. Where am I going wrong.
Can anybody suggest what I should be looking for/try?
Really is driving me nuts sitting for 30-60 Mins only to mis the approach every time!
I'll confess I'm probably trying to run before I can walk but I'd like to know what I am doing wrong.
Thanks in Advance
However with the IFR rules the last command comes "Turn left heading ...etc then expect vectors for the ILS approach/runway. I cannot whatever I seem to do intercept this I see no visual or audio confirmation. tried "Approach Hold" Button.
Generally, just fly right by.....So frustrating. I just can't get into the glideslope. Where am I going wrong.
Can anybody suggest what I should be looking for/try?
Really is driving me nuts sitting for 30-60 Mins only to mis the approach every time!
I'll confess I'm probably trying to run before I can walk but I'd like to know what I am doing wrong.
Thanks in Advance