I can answer that question from personal experience, I have been to that ceremony several times.
However, Long gone are the days where you could just show up at the venue sometime before the ceremony and expect to be seated. Now you have to arrive well in advance, not because of any formalities but because of the sheer number of people expecting to be seated on any given day.
Try to reach at max 2 PM in Winters, 3 PM in Summers. Expect multiple security checks.
Last but not least, The car park for that venue is quite far away. It is easily 1KM+. There is absolutely no way that you will be allowed to take your car, or any public transport to go farther than that. So it is a long walk. Be prepared for that.
Bonus Tip: If you have any friends in Pakistan that have family or friends in the security forces, they might be able to arrange premium seats for you if the coordination takes place in time, and not on the last minute. This is free as well.
And by the way, that ceremony is Awesome!
What do I need to do to see the Wagha/Wagah border ceremony from the Pakistani side?
Just show up well in time.
Credit:stackoverflow.com‘