Once you finish the first mission, you'll be good to get Face XP. The first thing you'll want to do is go back to the shop from the first mission and buy the Beaded Dragon chain for an extra 5% bonus; this does not conflict with the Minor Thug bonus you may already have.
Favors are on the map as yellow speech bubbles. Doing all of these with the extra bonus should get you to level 2. However, there's a good chance that one of the favors was already done without the chain, so if you need that small boost up, do the Police Case in the southeast area depicted as a blue folder. The second mission has a tutorial on drug busts; do one more outside of the case for the face upgrade.