Depends on what type of campfire

1.For outdoors ( not sure about indoors) shift+7, make a digging stick and getting 20 rocks( can use digging stick to or find them lying around or you can bash a small boulder with a makeshift hammer, Shift+ 8 - Build Fire Ring

2. Make a makeshift hammer or anything with "hammering 2", sheet metal ( default evac start can get it from destroying lockers - a chance to get if destroyed, pretty sure almost always a sheet if deconstructed -shift + 8 menu), then shift +7, look for brazier, build it, press "a" the place brazier.

For ease of use, shift +8, Mark Firewood Source and as long as there is wood( probably anything that is flammable but I use long sticks then logs) and you are nearby it will auto place wood to keep fire going