You will need to see a GP to get a referral for a dating scan, which is usually done at around 6 weeks. The next scan is done at 12 weeks, then 20 weeks. You will also need to see your GP or OB regularly for antenatal check ups. Depending on your risk level. I'm a low-risk pregnancy, so I see my GP every 4 weeks until 36 weeks, when I see the hospital every week until the birth. I also attended my hospital for a antenatal visit with the midwife at 14 weeks, and again at 20 weeks. But every hospital and dr varies with this.
You will also need to book into your hospital where you plan to give birth. It's best to ring them to find out when you'll need to do this.