White gold and Platinum are very different metals with very different properties, however they look almost identical.  Each has its advantages and disadvantages, but both White Gold and Platinum will require some maintenance.

White Gold is naturally grey in colour and is therefore typically Rhodium plated, which needs to be redone every 12-18 months depending on wear and tear.  It is naturally scratch resistant, however a lot of activities, particularly where metal comes into contact with your ring, will cause it to have little scratches.  White Gold will wear away if two rings are worn together, but it takes decades to notice any significant wear.

Platinum tends to scratch more easily than White Gold, however it does not require Rhodium plating.  It does still require yearly polishing to keep it looking its best.  Platinum is 30% denser than White Gold, so it is much heavier, and is ideal if you are having fine settings.  Platinum will not wear away over time.  Platinum is generally about twice the price of White Gold so if budget is a major factor, White Gold would be your best choice.