For simplex use, you can program whatever tone you want your family or other group to use. Or you can leave the radios in carrier squelch, that is, with no tone programmed. (If you use a tone, the regulations have required that you disable it momentarily in order to insure that there are no other conversations already taking place on the channel. If you were to attempt to contact another member of your party while another conversation is already taking place, not only can you interfere with their conversation, but their conversation can interfere with yours, resulting in frustration for everybody.)
In order to use a repeater, first you need permission of the repeater owner(s) to use their repeater, then you need to get the tones needed to access the repeater from them.
If there is a repeater on 462.6750 in your area, it *might* have the common travelers assistance tone of 141.3 Hz.
Go to mygmrs.com I think it is, and see if there are any repeaters in your area that might be available for your use. If there is, they may be free, or you may be asked to pay a fee to help with the costs of maintaining the repeater. Repeaters are not cheap to put up and keep up.
Before transmitting, be sure to acquire a license if you don't already have one
John
WPXJ598
Peoria, AZ