You can go the long way (Article 98.1) - move yourself, get a residence permit, prepare a package of documents, get approval for reunification from the SEF, send the documents of your family so they get a D6 visa at the embassy of the country of citizenship and come to Portugal to reunite with you.
It is a long and difficult way. Also you and your family will live in different countries for more than 6 months.

In this guide we want to tell you about a way where you don't need to be separated and live far away from each other.
You will:
✅ Come with your family and obtain a residence permit for reunification within Portugal (the family comes with you based on the Schengen tourist visa)
✅ Once you have obtained a residence permit, make an appointment at the SEF under Article 98.1
✅ Come to the SEF with your family and make an application
✅ Wait for a residence permit card

If this situation occurs, should you afraid of going to the SEF?
No, Portugal is surprisingly forgiving country - the biggest problem that you can have is the fine for an overstayed visa. The amounts of fines depend on the length of the overstay - you can see details here. But in practice, those who reunite are rarely fined.

By the way, the couple whose relationships are not officially registered can obtain a residence permit through reunification. However, you will need to provide evidence of domestic partnership - joint tax returns, common children, etc.