What should one do as a child who is getting married and want it to be simple and easy but parents are forcing to do things that are not allowed in Islam, like
1. Gold ring for men
2. Big events including mehndi event
3. Jahaiz
And they are giving "these are society standards, we have to do this, everyone does that" statement in argument.
Where do I stand in all this situation?

We need to explain them as much as possible and avoid haram things to get barakat in our future life and stay away from the unhappiness of Allah s.w.t. If one goes after society norms, then society norms have no boundaries. What is the extent? And they all indeed don't believe in Allah and Ahl e bait (as). In this case they are not answerable to anyone but we are answerable.