New delta type printer built, request assistance

Ok, so building a delta printer with a kit I purchased on line. Arduino/ramps based. Kit went together physically OK, but having a few problems.

#1, upon testing x/y/z axis motion, X and Y axis "arc" (I.E. appear to "swing" with the Z axis when adding/lowering value)

#2, unsure what version RAMPS board I have. Don't know what firmware needs to be loaded.

Arduino board is currently using marlin firmware provided by the kit supplier. Don't know if this is a good thing or not.

In short, kinda lost in the sauce, and can't find a tutorial direct enough for my skill level (low).

Thanks for your help in advance.

#1... I'm not sure what you mean by "X and Y axis arc"? Do you mean that when you command a Z motion, the effector also moves laterally in the X & Y axes? Do all 3 carriages move freely when power is off? Can you share a video?

#2... RAMPS is purely hardware. There is no firmware for it. The firmware (Marlin) goes on the Arduino board. My understanding is that Repetier firmware is better than Marlin on Deltas, but I doubt that you would see the difference until you know what you're actually looking for.