T-Mobile APN settings??need help


im a newbie at this,but i have an unlocked lg g Vista that i want to use on tmobile.I keep finding mixed apn's online,does anyone have the latest ones??also,does the tmobile sim card need to be in the phone in order to put the apn settings or can i put them without the sim card??my brother will let me borrow his active tmobile sim card but the apn settings dont save at all,is it because the sim card is not in the phone yet?or am i putting them wrong??many thanks for looking and trying to help.