how do i update my mac book yosemite 10.10.5 to latest.when i dont have any updates

The key to knowing if you have an upgrade path is the SUB-MODEL of your Macbook Pro which we do not know. You can quickly find it by doing "About this Mac..." from your Apple menu:

In the example, the SUB-MODEL is "(13-inch Mid 2012)"

..yosemite 10.10.5 to latest.

If you are currently running 10.10, you should have at least one upgrade available. All Mid/Late 2007 though Mid 2009 now running OS 10.10 can run up to macOS 10.11 El Capitan. If it is Late 2009 though Late 2011 it can run up to macOS 10.13 HIGH Sierra. It can be a new as Mid 2015 and still have shipped with 10.10 Yosemite! So we're sort of stuck.

So, without knowing which of the dozens of Macbook Pro variants you have, it is hard to give you a precise answer to "can I update/upgrade?"

Remember, we are end users like you with no way to know your equipment details if you do not provide them. And we are really bad at guessing!!

4tunesoul wrote:

how do i update my mac book yosemite 10.10.5 to latest.when i dont have any updates

The end of the line for your OS X Yosemite is 10.10.5 (14F2511) (July 19, 2017)