If you are on a gamejam with short time and you dont want to code basic stuff like a pick up system or even how doors work in UE4 then you can simply use this tool #FPEkit. I made some walking simulators in my time here but I used unity and didnt got into coding but with the easy to use Blueprints (visual scripting language) in UE4 I got into it. It may seem as a lot of work at first but this tool can cut some time with examples and plug and use codes. Everything to get you started with

First Person Exploration Kit is a starter package to create a First Person Environmental Exploration or “walking simulator”.
It is easy to use & cheap. It is build for the Unreal Engine 4.
https://kai20.itch.io/exploration-kit

If you want to see the tool you can download the demo or simply watch that video below