To get these achievements you'll have to play a lot of ranked multiplayer matches. Score as many points as you can each game to get these faster. You can check the scores ingame by pressing . Take down as many of the enemy as possible. In objective games, make sure to be the one that scores the flag or secures the HQ, for example. Don't teamkill, as a punishment takes points away from you. You can view your current points by going to 'Leaderboards' and then 'Global Leaderboard'. If you have played ranked matches then the first page that comes up will show your rank. The star indicates your points, and you can press to view more detailed statistics.