Welcome to the MPCNC community.
I have recently completed my machine and it was great fun.
Am enjoying learning how to control it and making a real dusty mess.
Yes. There is support for an SD card, if you buy the Reprap Discount Full Graphic smart controller (or an equivalent).
This has a larger screen than most common displays, a rotary/push switch to step through the menus, a buzzer and a ‘kill’ switch. It usually arrives with twin cables but make sure you get the small adapter which plugs into the RAMPS board and provides the necessary twin sockets for the cables. The controller also has an SD card socket on its underside, near the board edge. See photos below.
And, Yes. The option ‘Print from SD card’ is available when CNCing, as well as when 3D printing. Both processes read the gcode file that you will have saved to the SD card.
Good luck and enjoy it all.