You do not have sufficent lighting to keep an anemone. I think a lot more research needs to be done on your part. You need to have good lighting (search anemone lighting on this forum for specifics), and you need decent water quality. 0 AM, 0 Ni, <10 Na. How long has your tank been setup? What is your water chemistry right now?
As for water changes, nothing should change. You should mix your salt and water to the desired SG at least 24 hours in advance with a power head. Preferrably around 48 hours.
As for current, you said you have a power head - how large? You should aim for 20x turnover rate in your tank. So in total with a 30 gallon tank you should have 600 GPH pumping through you tank.
I would get more LR as well, you need around 1 lb per gallon of water. I know you can get away with less, but LR is the best filtration you can buy.
Feeding an anemone depends on the setup. With less lighting you should spot feed them once a week, if you have very nice lighting system, feeding at all is probably unecessary.
I think in order to sustain an anemone long term (measured in years not weeks/months, b/c they can live a VERY long time) you need proper lighting, proper water chemistry, and you need to have a stable environment. IMO you are setting yourself up for failure, research, get your tank ready, THEN purchase the anemone - if you rush into this you will have a dead anemone and probably dead fish on your hands.