What this covers
A Shia marriage usually moves through the same broad stages: a proposal reaches the family rather than the individual, the families and the wali discuss expectations, identity and intent are established, a mahr is agreed, and nikah is performed with the required witnesses. Where and how each stage happens varies by family, by marja and by the couple. What varies most in practice is how early the family is involved, and how much of the process is expected to be private between the couple. Those are worth agreeing explicitly rather than assuming.