How do you think you can support a baby, if you can't even support yourself? You will need to pay for shelter, food, clothes, diapers, furniture, etc for your baby for the next 18 years. Are you ready for that? Nope.
What should you do first? Uh...get married. If you're not financially independent and won't be able to provide a good home for your child, then do the baby a favor and don't get pregnant yet. You're just too young. Wait until you're old enough, independent enough, responsible enough, (and married), before you have a baby.
It's okay to want children, however you are far too young. At your age you don't have the financial means and the maturity to raise a child. More than likely your parents would get stuck taking care of the baby. Finish high school, if you already have get a degree or find steady work. Dave money, find a guy who you fall in love with and he falls in love with you, get married and have children. This sounds rude but you're 17, not even an adult. What makes you think you can raise a child?!