You need to get to about 270 Steem Power. SBD doesn't add influence. 270 SP costs about .21 btc, or $130 USD, currently to get to the .001SBD minimum threshold, if my rough calculations are correct.

Until then, yes you can still get curation rewards. Go to your wallet, then click rewards, then curation rewards, and you can see that you already got a couple. You can get more by voting between 20-40 times a day on posts that will become popular, within the 15-30 minute window. You won't get much most of the time, but you will likely notice a little trickle after a while if you keep that activity up.