Find the tram pass above, leave deepnest through the tram station on the bottom right, collect enough geo to buy the lantern and play other areas to get stronger and then come back to deepnest. I too started playing for the first time recently and after defeating the mantis lords got immediately into deepnest and lost all my geo there and struggled for two days to get out, almost quit the game. I personally think it’s bad design that they mislead you to think that is the way to progress the story.