You can manage & track your card collection and decks once you create an account and login.
When do I use this ability?
You use it before the game begins. You’ll put Force Field onto Private Trailbreaker, then shuffle the rest of your deck and draw 3 cards for your opening hand.
Source: Wave 2 and 3 FAQ
For Wave 3 Ratchet, Ultra Magnus, Trailbreaker and Wheeljack. Do you search for their related card before you draw starting hand or after?
Before the game starts, find their related card, shuffle, then draw three cards for your opening hand.
Source: Rules Roundup 2019-04-26