There is no need to declare CurrentAsset if Asset is always the current asset. Asset is a string, so you can use it in your printf function.

var C = series(priceClose(0)) is wrong because series() is a vars.

var C = priceClose(0) is correct because priceClose(0) is a var.

Finally, do not be afraid to experiment with coding. Try a code, see if it works, and if not, find out why. Master your craft.