The latest software update is to fix issues for macbooks 2019 an 2020 or later. I have a 2014 macbook so do I need to download this latest update?

If your Mac shows an update is available then you can update it if you wish. If you don't you may be missing out on any security updates. Whether you update or not is your call.

There are no 2014, 2019, or 2020 MacBooks, so you must be talking about MacBook Airs or MacBook Pros.