Wanting to change my name

hi so you may or may not regonise me for a post i did a bit ago but ive figrued it out (thanks for the help).

i want to change my name to Luka or Luca i really like it and it makes me feel less fem. the problem is that i dont know how to go about changing my name with other people. i dont know how to tell my friends or family. im scared to do so but also hopeful. any help would be greatly appreciated!

or

i need help to find a way to tell my friends and family that i want to change my name