I set up an account 3 days ago, no friends added as yet

there was a list of people i might know, some family, some local
and about 30 others off the various forums, list was quite long.
How do they know all this ?
Do you just add customers and keep friends seperate ?
Mine is Andrew Briscoe Cleaning,
just have my contact details and pic of new Maxx 470

Do you let customers know your details, add them, so they can contact you,
keep them informed of offers etc.
Andrew