Flash Player has stopped support of mobile devices. You can't install flash player on any mobile devices.
I heard someone stating that it worked on Lollipop on their nexus, I have been unable to find a posting on XDA for Samsung. I have not used Flash for a few years now and am on Lollipop and dumped my Titanium Backup of it, so I am kind of confused as to why you need it. Anyways.
If its not going work, it just won't install, it cant hurt your phone.
That is the last/latest version i think. Adobe Flash Player 22.214.171.124 4.0+ | Nexus 7 | XDA Forums
Has shown to work on Lollipop: Flash player WORKS on Android 5.0 Lollipop!!… | Nexus 7 (2013) | XDA Forums
Granted you have a Samsung, the app is generic and not for any one specific phone
You will have to side load it though