I do not know much about heating configurations. Do I need to add a heatsink or better fan? Or will this case take care of my needs? I plan on adding a good GPU in the near future as well. Please let me know what you think, thank you.
While the 3900X can be cooled by the Wraith Prism cooler that comes with it. It definitely struggles to do so adequately. The 3900X is a high core count CPU and because of it, requires additional cooling.
My recommendation would be an AIO. We carry a wide selection of AIOs that would work with your build, but I'd recommend a Kraken X63. https://www.microcenter.com/product/618679/nzxt-kraken-x63-280mm-rgb-water-cooling-kit
Otherwise, I think your build looks great!