my hard disk is getting full, I do backup on a regular basis, what should I do to clear space for my hard disk?

When you run out of space on your HD you will need to install an external disk. Then you can transfer files, such as photos or music files to the external disk and that will allow you to delete them from your HD to clear up the needed storage space. These days these disks are cost effective, compact, easy to install with vendor provided USB cables and most do not require external power. You may have to reformat it though. There is a large selection of disks to choose from. This solution will allow you to easily have the storage you need.

Hi,

If your MacBook Pro HDD is able to replace, clone back up with Carbon Copy Cloner or SuperDuper! on external drive, then reinstall bigger HDD or SSD on your MacBook Pro and boot from external clone backup to restore from clone back up to new bigger internal drive.

If your MacBook Pro HDD is not able to upgrade, move big files like music and Photos library to external drive then select the libraries with option+click when startup the applications, Music and Photos.

The short answer is remove data from your Mac. Apple has a more detailed list in Free up storage space - Apple Support

Your Time Machine backups will eventually be replaced by a later backup so if you move content off your computer and you want to archive it the best practice is to have several copies of it on other repositories, such as an external drive.