Re: Is it call "the head platform gate"
If it's a terminus, it's not too difficult. You're either at the station end of the platform or the non-station end. However, if you're at a station somewhere along the track it's more difficult. I would have had to say to my friend "Go to the platform and then stand facing the tracks. Then walk along to your left all the way to the end. That's where I'm waiting." Having said that, if it's a platform or station you both use regularly, then you will both know from which direction the train enters the station. In that case, you can say "I'll be at the front [end] of the train" or "I'll be at the rear [end] of the train".
Remember - correct capitalisation, punctuation and spacing make posts much easier to read.