PUT THEM ALL IN CONFIDENCE IMO TBH~!!!11
Really though, soft cap your speed (and agility too if it isn't), then start working on Vision and SAs. The sooner you soft cap vision, the better in the long run.. the sooner you start investing in SAs, the sooner you'll start performing really well.. it's a trade off and up to you. Just do aim to soft cap Vision at some point. And the best SAs to work on are Super Vision and Shutdown Coverage. Don't neglect your other 'secondary' attributes either: train Jumping, Catching, Strength and Tackling with your daily training, and don't be afraid to spend spare points in them (once you're happy with your Vision).
Tactics-wise, you should ask your DC, as personal tactics settings really need to compliment your team's settings & play style. But in general, I've found that Close/Medium is the best defensive setting (you'll try to stick to the WR and swat anything that comes that way, allowing very few yards) while Medium/Aggressive si the best for stat whoring and getting picks (you'll stay a few yards back and try to close the distance when the ball's thrown; sometimes you'll get the pick but usually you'll have to settle for a tackle).
