nope, SER is not the same as BER
SER stands for Symbol Error Rate whereby lets assume a QPSK modulation scheme shall we?
In a QPSK modulation scheme, 2 bits would be mapped into one symbol. Mainly 00 01 10 and 11. Thus, the symbol error rate would be the error associated with the symbols.
Lets say we transmit a symbol 00 and there are some noise is in the system. The decoding part decodes the symbol to 11 instead of the actual symbol of 00. The Symbol error is 1 for this case as there's just a single symbol error but the bit error is 2 since both of the bits in the symbol is not the correct bit.
For you to plot the BER vs SNR curve, you would need to know the number of bits in the symbol itself. Else, you would just be plotting the SER