My mom and dad are getting divorced please help?

im 13 and have a brother in college hes 19 and my little sister is 6 turning 7 and my other brother is 16 turning 17 and my dad told my mom that he was leaving us and what if he does this just happened today im kinda said but kinda not because my dad never really liked us or cared but anyways will the goverment pay my mom for me and my sister some money cause my dad left us my dad said he will go to mexico to not pay child support but i dont know how that works can you please help me out im really worried oh and also if my dad stays here in the united states and gets a house or apartment do i get to choose who i get to stay with because i dont want to stay with my dad i prefer to stay as i am with my mom someone please help me tell me what i need to know about this