How do I navigate a professional career when no one in my family has?

No one in your family walked this road, so you are learning the professional world without the guides most people take for granted. That is genuinely harder, and you should name it honestly rather than wonder why it feels so lonely. You are doing something new for your whole family, and there is weight in that, but there is also something to be proud of. What you lack is not intelligence or worth. It is a network and a set of unspoken lessons that others got at the dinner table. The good news is that all of it can be gathered from outside your family, from mentors, from watching, from asking. You will build your own version of what others inherited, and because you built it yourself, you will understand it more deeply than they do. Start by finding one or two people ahead of you who are willing to answer your questions, and use them without shame. You are not supposed to know things no one taught you. Ask, watch, and give yourself patience, because you are learning the game and playing it at the same time. You are not behind. You are the first, and the first always has to walk the road before it becomes a path.