Marriage is pretty secular in my country, New Zealand.
If you have a religion, or cultural tradition, that dictates how a marriage should be held, then you are free and welcome to have your marriage in that fashion. For example, the 3 days of celebration for some..i think it's Hindi (I could be wrong)...marriages - no worries, celebrate away.
The only things that need to be followed are:
1 - you need to have applied for the marriage licence 3 days prior
2 - No co-ercion into marriage
3 - you both need to be of legal age - 16.
4 - you can't already be married
5 - if you have been - you need to be divorced from the previous spouse. (No poly-marriages).
Exception is - if you are changing your Civil Union to a Marriage (same-sex marriage has been legal since 2013, but CU's preceeded this) - and are marrying the person you have a Civil Union to - no need to divorced (if you are marrying a different person - you still need to divorce from the CU)
We don't mind if you want to marry in a church, at a registry office, in a forest, at home, on a boat etc. Nor do we dictate how it should be done - aside from the above, and having a registered celebrant/clergy member perform the ceremony.