I can read your posts just fine through google translate. I know some Spanish, but I won’t torture you by trying to write anything but English. . Hopefully, the translation back to Spanish works well enough for this conversation.
The MPCNC and LowRider2 both use 5 motors. So you will need another motor eventually.
The recommended firmware for RAMPS is Marlin, configured by Ryan. I would not start with the dual endstop version, because it is more advanced. You can run two motors off of a single driver by wiring them in serial:
The firmware from Ryan’s github already has been configured for CNC work. It does not need any additional configuration. You will need to adjust the current on the DRV8825s though. If you don’t adjust the current, they will overheat, or “skip steps”.
You should install all the jumpers under the drivers to enable 1/32 microstepping. Otherwise, the machine will try to move way too fast.
The RAMPS boards are very fragile. It is very possible that either the drivers or the mega have broken. The only way to test is to go through the setup and see if they work.
There are more details about getting the Marlin firmware and flashing it in the docs: