Personally i prefer Villa map because it's small and great for close quarters.
Pick a gun you like and are GOOD with.
and choose games such as:
Team deathmatch (deathmatch if you good..)
as theyre good for multiple kills in each match!
Avoid games like; Attack & Defend as they're not very long games.
Also, even though the Shield seems like a good option to use to stay alive, i don't recommend it as experienced players can manouver round you.