I am a Scorpio rising but I feel I should be a Sagittarius. Do planets in my first house influence this?

Jupiter anywhere in your first house will give you the traits of Sagittarius. As will Ur give you the traits of Aquarius. This is how you'll see yourself in your early years, and how others see you. You tend to be optimistic, lucky and say the first thing that comes into your head at times. You may also put on a bit of weight. As you get older you'll grow into your Sun sign. Look at your 4th house as well, which sign is on the cusp? This house shows, among other things, how you start off your life and how you finish it.