How do I mine a specific block, sometimes I want to mine spruce wood but it mines every type of wood?

It depends on what version you are on.
If you are on version 1.13 and above to do this you would do
#mine oak_log
#mine spruce_log
If you are on 1.12 or below you would do
log:0 = Oak Logs
log:1 = Spruce
log:2 = Birch
log:3 = Jungle
log2:0 = Acacia
log2:1 = Dark Oak.