I usually stutter less in front of my dad, mom , gf and friends in general but it's not the same when talking to strangers.. any tips ?

I usually stutter less in front of my dad, mom , gf and friends in general but it's not the same when talking to strangers.. any tips ? I remember when initially into my relationship , I used to stutter a lot but as days passed, my stutter reduced and same in front of my friends. ( almost like stuttering once within a 1 hour convo.) is this just confidence issue which stops me from being fluent?? Also I stutter even lesser when conversating in English ( I am Indian so my mother tongue is Hindi which is quite difficult)...I have a mild stutter which increases talking to strangers.. can I cure this by increasing my exposure to public speaking ? what can be my possible root causes of stutter? ( none of my siblings , parents or grandparents have stutter ..its just me ) For example : my name starts with "Ku" which is harder to pronounce in front of a teachers but its a cake walk when talking to my family members to whom I am familiar with.