Formal:
* Podemos ser amigos? (This is the most direct translation and is appropriate for formal settings.)
Informal:
* A gente pode ser amigo? (This is a more casual and friendly way to ask.)
* Você quer ser meu amigo? (This is a more direct and personal way to ask.)
* Podemos ser amigos? (This is also acceptable in informal settings, but it sounds a bit more distant than the other options.)
Other options:
* Que tal sermos amigos? (This is a friendly and informal way to suggest becoming friends.)
* Gostaria de ser seu amigo. (This is a more formal way to express your desire to be friends.)
The best option for you will depend on the specific situation and your relationship with the person you're talking to.