Your processor is not the (main) issue. Your 12 year old 0.5 GB vRAM, DX10 video card is.
It does not support DX11 or Shader 5.0 which are a must to run the current version of the engine. You say DX12 but that’s what your OS can do, not what your video adapter supports. There is a *hack *that would allow you to run an older version of engine (4.16 / 4.17 or thereabout) but since you want "a highly realistic spaceship", you will not be able to achieve what you want. Or you will need expert knowledge of materials in order to work with the upfront limitations.
While many consider 16GB RAM to be a reasonable minimum (and rightly so!), you can get away with using 8GB but it *will *test your patience, especially that your machine is likely to rely on an old fashioned HDD rather than an SSD. If you exercise patience, the 8GB will allow you to learn the basics of the engine for as long as you stick to simple scenes and highly optimised assets.
To sum it up, you can run the engine if you up the RAM to 8GB and get another video card. It does not need to be cutting edge - a used $50 GPU supporting DX11 will do just fine for learning; like a GeForce 960 or similar.