Answer:
A conditional permanent resident can leave/enter the US at will without the risk of being denied entry by an immigration official the port of entry. You have right to apply for government-sponsored financial aid for education, you will pay resident tuition for university and college compare to a foreign national’s tuition. You are permitted to work in any company that chooses to hire you. Yes, you will obtain your social security number.
Your son, as a permanent resident, would be required to register with the Selective Service System. We have no military draft at this time in the US. If a draft were reinstated, it is possible he could be drafted unless he, by then, has aged-out. The US has voluntary military forces. A permanent residents may enlist in any of the military branches if he or she applies and meets the requirements (i.e., age, height, health, moral character).