If I pick wood elf as my race do I also get the other benefits from just the elf race? Like the wood elf gets +1 wisdom but does that mean I also mean I get the +2 dex from the non subrace elf?
They do combine
Those races with sub-races are very limited in racial abilities without them. They are designed as a combination of factors to determine your full race.
Elves are always dextrous, live a long time, trance instead of sleep, etc. However, wood elves are wise in the ways of the woods and perceptive, high elves are intelligent and in tune with magic, and dark elves have a very strong force of personality. The differences as listed here only go in to the nuances of the sub-races themselves by a small margin, but the idea is still presented. The base race (elf in this case) is what is common among all members of that race. The sub-race is what separates different members of a base race from each other both genetically and culturally.