my mac is from 2015 and when i try to manually update safari through the app store it says theres no updates and my laptop doesn't show me a software update option in system preferences

Safari is updated when you upgraded the operating system on your Mac.

The model year of a MacBook Pro is available at Apple menu > About This Mac.

An Early 2008 through mid 2009 MacBook Pro can be upgraded to El Capitan 10.11.6 but no later version. See: https://support.apple.com/en-us/HT211683

A mid 2010 through late 2011 MacBook Pro can be upgraded to High Sierra 10.13.6 but no later version. See: https://support.apple.com/en-us/HT211683

A mid 2012 through early 2013 MacBook Pro can be upgraded to Catalina 10.15.7 but no later. See: https://support.apple.com/en-us/HT211683

A late 2013 and mid 2014 can be upgraded to the latest  version of Big Sur macOS 11 but no later. See: https://support.apple.com/en-us/HT211683

An early 2015 or later can be upgraded to the current version of Monterey macOS 12. See: https://support.apple.com/en-us/HT212735

There may not any update for your Mac

Newer versions of macOS comes with newer versions of Safari.