Chosen Solution

Want to record my own voicemail greeting not the generic one

There are multiple ways to do this. On an apple device go to phone>voicemail>greeting then choose an option or record your own. On other devices most carriers have a number to call to access a voice-mailbox. If it is previously set up you enter the PIN and there will be an option if you listen through to choose a greeting. Listening to the options presented is important but it can always be changed.