I got started on Blender last September. I bought a Mac 3.8 GHz Intel Core i7 8 cores, 32 GB 2667 MHz DDR4, with AMD Radeon Pro 5500 XT 8 GB graphics card. I am using version 2.90 of Blender and unfortunately with the Cycles render mode, AMD Radeon cards are not supported. The rendering execution time is therefore longer. Do you know if Blender will adjust this in future releases. Do you advise me instead to switch to Windows to have a compatible graphics card.
Preferences > System > Cycles Render Devices and select OpenCL. You can also try AMD ProRender: https://www.amd.com/en/technologies/radeon-prorender-blender