I'm about to immigrate under EB3 visa (employment-based green card), and I'm applying for some unsecured credit cards (CreditStacks, Advancial, and American Express Global Card Transfers - but I also accept other suggestions if any).

I read here that a good diversity (credit mix) will help improve my score.

Assuming that I can get one unsecured card, does it still make sense to also get a secured card?

Will it help my credit-score if I get 2 unsecured cards?

Additionally, for getting a good mortgage rate in the future, should my spouse also worry about building her own credit score?