Planning to get married – how do you manage your finances, portfolio and assets in your marriage?

Hello everyone, I am currently 25 years old and am planning to propose to my girlfriend in January next year. Then we would have been together for almost three years. We've been living together for about a year and four months and so far our relationship has been really harmonious. Of course no one can predict the future, but I can very well imagine a long-term marriage with her. Nevertheless, I have recently been thinking about the topic of finances in marriage