What should i do if i am trying out contact lenses for the first time and feel a slight nauseousness?

You are adjusting: your lenses. Contact lenses tend to create more sharpness of vision, and it may cause nauseousness initially, until your eyes adjust. So make sure that you use your rewetting solution, to make sure the lenses aren't drying out, and are comfortable. So limit your use of your contacts to a few hours or less on the first day, and add another hour and see if that helps reduce nauseousness.