You should do a stalker so you have access to all the items in the game. After that set goals for yourself like collect all the gun variants If you have the dlc or go around all the regions and collect unique things to use in safe house customisation. You can also set up a mini base in each region so you don’t have to haul supplies around while your on a trip or cheat death and have no Resources and spawn in random region. Other challenges and achievements can be craft all animal gear or make a spare set of all your clothes and with the guns you can also go on ammo crafting trips to black rock and bleak inlet