Hello! To identify your Tier, please open Gear Hub and check out the latest Tier in which you can make purchases. That will basically be your Tier.

The Blueprints drop rate depends on the Grade of your Weapon/Mech. The more valuable your piece of the Content is, the lower the chance it will be dropped.

Thanks. I'm tier 3 then. Tier 4 has a flashing gold star saying 19/24. How do I know what that means/what I need to focus on to get to the next tier? 

Hello! Acquiring or upgrading Mechs and Weapons from your Tier brings you the Tier Stars. You can learn more about the Tier system by pressing the ⓘ button at the bottom left of the Gear Hub window.

*(DOOM)* 

By not understanding you understand perfectly!  There is absolutely no logic behind the blue print system and hasn't been since day one over 4 years ago. There is no reason at all for getting blue prints not needed. Wait until you get blue prints for mechs and weapons that are already maxed out!  The blue print system is broken and Plarium would rather produce more mechs and more weapons than fix what is broken.  All it would take it is to allow players to transfer blue prints to other mechs and weapons, something Plarium refuses to do.