I need some advise

[cancerkd]

PLEASE ANYONE WITH ANY INFORMATION PLEASE HELP!!!!!
My girlfriend and I have recently decided to split and go our seperate ways. We have a 19 month old son who is going to be caught in the middle of our seperation.  She is unemployed and about to get evicted from her apartment.  I need to know what steps I need to take to ensure that she doesnt leave the state with my son.  We have lived together from day one of my son's life and I am not ready to give up my rights as a father.  She has taken him away before and threatend not to return.  She told me she was taking him to see his family in New York and then she didnt want to come back, she said out there for 2 months.   What can I do to make sure that doesn't happen again.  Also I have my own place now, and I am currently a Desk top Support Specialist for Toyota Motors.  I would like to also get information on how to get full custody oif my son, at least until she gets a stable job and a place to stay.  PLEASE ANYONE WITH ANY INFORMATION PLEASE SHARE IT.  tHIS IS A VERY STRESS FULL TIME FOR ME AND ANY ANSWERS, OR ADVISE WOULD MEAN THE WORLD TO ME.
tHANKS.