"Atleast" is an incorrect spelling of the phrase "at least."
"At least" is a phrase used to indicate the minimum amount, degree, or level of something.
ATM as used in casual, everyday texting is most commonly short for "at the moment". It could also be used to mean "automatic teller machine", which you can use to get cash from a bank account.
"Lifes" is an incorrect spelling of the word "lives."
"Lives" is the plural form of "life," referring to the existence of multiple beings or the multiple experiences of existence.