After the adventure with the bloodthirsty fish, Artyom sets off in search of a train car. The following page of Metro Exodus guide discusses this task.
Proceed forward. After a while you will see anomalies - they are deadly dangerous and even if you are in a vehicle, you can easily die. Wait until the discharges are off the road. At some point, you will see a fork of the tracks - exit the car and use the lever to move the tracks.
When you go down the right road, you'll come across a base of bandits who live in old cars. You have to get rid of them - your weapon has probably longed for more victims, so kill the enemies. However, be vigilant, as there are quite a lot of enemies and they have a lot of firepower.
Head to the top, where you'll find a lever that will raise the gate and allow you to catch the car. Move with the wagon towards the train with the rest of your team.
You will pass along a few anomalies again - avoid contact with them and stop if necessary. When the road is safe, continue your journey. After a short ride, you will reach familiar' faces - talk to Miller about the next task.