Hardware updates continuously, and software pushes its boundaries accordingly. Specifications may vary from year to year, but generally, a PC with a dedicated graphics card, 8 GB of RAM (16 GB is better), and an SSD is required. More info on the minimum requirements of Revit can help to orient when buying a new computer:
https://www.autodesk.com/it/support/technical/article/caas/sfdcarticles/sfdcarticles/ITA/System-requirements-for-Autodesk-Revit-products.html .