how can i change from absolute path to relative path. i want to share my file and materials as zip folder to a group so that they can us the file on their computer.
You can find the option under file -> external data. There you could alternatively also pack all textures into the .blend file directly, which might be the better option, if you want to share the file packed in a zip.
By default blender uses relative paths. To make sure this is still set as default goto preferences(Ctrl+comma on 4.+, or F4->preferences or edit menu preferences) Click Save & Load on the left hand side. In Blend file panel under default to section make sure relative paths is checked.