If the chip near the USB port says 16u2 on it, the CH340G drivers will not help!
If changing the cable does not fix it, I would suggest that the board is defective.
In terms of what to recommend new users, tbh I think the chinese clones with other serial adapters are a better bet; the 16u2 is very easy to damage if you abuse the board (electronically), compared to the CH340G or CP2102.