If you are going to get married in a sunny location then a light tan is helpful as you will generally look more radiant and healthy. Also if your skin is a bit darker it is less reflective which will help in the sunlight. If you are going to spend a few days in the sun before the wedding then having an existing tan will reduce the risk of sunburn or red skin as you already have some tan, of course wearing some sun block is essential.
If you are going to get a fake tan get it done by a professional who sprays it on. Many of the cheaper creams have colours that aren’t natural, they leave you looking rather yellow or too orange and if it is self applied it is easy to miss a spot and achieve a rather unflattering streaky look.
If you plan on coming abroad and getting a tan in the days before your wedding that’s fine but please be careful not to get sunburnt. A red face from the sun is not very flattering and if you’ve overdone it in the sun the skin has a tendency to sweat more. Worst of all avoid getting burnt and risking peeling skin!