Formal:
* Nous nous ressemblons. (This is the most literal translation and means "We resemble each other.")
* Nous avons des points communs. (This means "We have common points" and is a more nuanced way of saying you have similarities.)
Informal:
* On se ressemble. (This is a more casual way of saying "We resemble each other.")
* On a des trucs en commun. (This means "We have things in common" and is a very casual way to say you have similarities.)
Other options:
* Nous avons beaucoup de traits en commun. (This means "We have many traits in common.")
* Nous avons la même façon de penser. (This means "We have the same way of thinking.")
The best way to choose the right phrase depends on the situation and your relationship with the person you are talking to.