What would the process be like for coming to Beijing Capital Airport for the first time?

Hello I will be going to PEK on a tourist visa. My trip goes from BWI -> SEA -> PEK. I will be flying with Hainan Airlines. What is there to expect when i arrive and where would I go and what will I have to do? Is there anything thing I need to be aware of or watch out for? It is my first time flying international, by myself to visit my boyfriend.