Minimum system requirements for Lightroom Classic and Photoshop
Windows Machine
Windows 10 Pro 64bit
CPU - Intel® or AMD processor with 64-bit support*; 2 GHz or faster processor (Intel i3, 15 and i7 or AMDRyzen)
RAM - 4 GB of RAM (12 GB recommended) DDR3 or above
Disk Space - 2 GB of available hard-disk space for program installation.
Monitor resolution - 1024 x 768 display
GPU – With DirectX 12 or OpenGL 3.3 support, 1 GB Video RAM (VRAM). 2 GB of dedicated VRAM (4 GB recommended) for large, high-resolution monitors, such as 4K- and 5K-resolution monitors.
MacOS
CPU Multicore Intel processor with 64-bit support
OS - macOS 10.13 (High Sierra), macOS 10.14 (Mojave), macOS 10.15 (Catalina)
RAM - 4 GB of RAM (12 GB recommended)
Disk Space 2 GB of available hard-disk space for program installation (cannot install on a volume that uses a case-sensitive file system or on removable flash storage devices).
Monitor resolution - 1024 x 768 display
GPU With macOS 10.13 or later with Metal support, 1 GB of Video RAM (VRAM). 2 GB of dedicated VRAM (4 GB recommended) for large, high-resolution monitors, such as 4K- and 5K-resolution monitors.
When you consider the required specs, which a fairly basic, you will see that most current new machines will provide more than the actual requirements of Lightroom and Photoshop . You can choose either a Windows or MAC platform. Your basically looking for a machine that has the capacities stated above.
One of the most important aspects to consider is the speed of your hard drive, you should really consider an SSD, or at least a combination of SSD and conventional hard drives. As is RAM, the more the better.
If you need a hand in identifying machines that fit your budget, which you haven't mentioned, let us know.