@kdragon you can get an Arduino Mega from loads of online shops that will ship internationally such as:
Or
I don't know of any Venezuelan suppliers unfortunately. On a cautionary note, this is an ambitious first Arduino project for anyone and I might suggest that if you just want this for PCBs it might be simpler and cheaper to buy a CNC kit or pre-made one such as this or something similar:
Even making one yourself unless you have at least some of the parts like the stepper motors you will be looking at about a $300 build. Lead screws, nuts, stepper drivers, and bearings etc all add up very quickly! So weigh up time versus cost versus satisfaction of making it yourself. Hope this helps.