In order to make any changes, including setting goals, to your Google Analytics account setup, you will need to have administrative access to your account. Someone has administrative access to your account, and if that’s not you, then you likely have ‘read only’ access to your account, meaning you can view data but not make any changes to the setup.
A quick way to find out if you have administrative access to your account is to log in to Google Analytics, view the website profile you want, and check if there is an ‘Admin’ link in the top left of the page on the orange banner.

If you don’t have administrative access to your account, you can request it from your website administrator or get them to make the changes you require.