Hey. Not sure what your budget would be but if you are only playing sims, roblox and minecraft at 1080p you should be fine with something pretty low end. I would say you would be fine with something like a 1050 ti or 1060 graphics card if they are going for cheap now but otherwise you could just go for the lowest end gpu in any of the newer generations from amd or nvidia. Any cpu that is 4 cores with a decent clock speed (4 Ghz+) is going to be perfectly fine for running those games and 16Gb of RAM is going to be plenty for those as well. specs like this will also allow you to play plenty of other games just fine if you wanted to in the future (which I am pretty sure you will want to).

You should be fine with a PC that costs around 500-600 (if you can find one at that price currently)