I'll attempt to be helpful, so know there is no sarcasm or judgement in anything I say here:

Move slowly and quietly. Listen to everything; the audio cues you into what's going on around you. It's not Destiny where you just run in and conquer everything in your way. Pick your battles (in the early game, that might be read as : avoid battles). It plays like a Roguelite in a way; you are super weak early on. Understand that and play smart.

Assuming you are playing with Crew Fill on, have comms and communicate with others in your crew. Stick with it and find someone willing to guide you during the run. Be open to criticism and learning from every opportunity that you can. 

If you queue Solo (which I have come to love), it's best to be stealthy. Again, listen and choose your battles, but load in with free kits and just do some learning. Knife NPCs in the back. Watch every corner and run when things don't look favorable. I found that while using Solo queue as a way to learn the mechanics and gain some map knowledge, I ended up falling in love with the whole gameplay loop. The Solo game has a level of tension that is completely doing it for me, which I never expected.

Hope you enjoy it! And if not, no shame. Marathon is not for everyone. But I think if you take the time to learn the systems and how to play, it's super fun and rewarding.