Back up my Mac with Time Machine

jeppymo wrote:

i am trying to back up my Mac to my time machine.

Here are the instructions for configuring and performing Time Machine backups.

Back up your Mac with Time Machine - Apple Support

Also provide technical details about your computer . There are thousands of different Mac computers and a solution to what you are asking may depend on the model, sub-model, and OS version on your Mac. And we are terrible and mind-reading and guessing what you have.

"About this Mac..." at the left end of your menubar is a great place to quickly find basic equipment details:

For security reasons, please DO NOT post your serial number.

Apple has these recommendations for asking questions here, where we cannot see not touch your computer: