You can simply make the two unnecessary lines INVISIBLE using the properties of the indicator, once installed on the chart, without changing the code workings. Just replace the RETURN line to get rid of STYLE:

RETURN VWAPweekly as "VWAP Weekly", VWAPmonthly as "VWAP Monthly", VWAPyearly as "VWAP Yearly"

As for bands, you did not tell about your error, But there’s no reason not to be able to draw as many bands as you want (Band2UP/Band2DN, …), this is the same code modified (without removing any original calculation), with just 1 band and the RETURN line reflecting that addition:

//PRC_VWAP weekly,monthly,yearly
//28.09.2016
//Nicolas @ www.prorealcode.com
//Sharing ProRealTime knowledge
defparam calculateonlastbars=10000
//calculation periods
if DayOfWeek=0 or (dayofweek[1]=5 and dayofweek<>5) then
   weekbar=barindex
endif
if month<>month[1] then
   monthbar=barindex
endif
if year<>year[1] then
   yearbar=barindex
endif

once dWeekly  = 1
once dMonthly = 1
once dYearly  = 1
dWeekly  = max(dWeekly, barindex-weekbar)
dMonthly = max(dMonthly, barindex-monthbar)
dYearly  = max(dYearly, barindex-yearbar)

VWAPweekly  = SUMMATION[dWeekly](volume*typicalprice)/SUMMATION[dWeekly](volume)
VWAPmonthly = SUMMATION[dMonthly](volume*typicalprice)/SUMMATION[dMonthly](volume)
VWAPyearly  = SUMMATION[dYearly](volume*typicalprice)/SUMMATION[dYearly](volume)
Band1UP     = VWAPweekly + ((std[20](VWAPweekly)) * 2.0)    //UPPER band
Band1DN     = VWAPweekly - ((std[20](VWAPweekly)) * 2.0)    //UPPER band
RETURN VWAPweekly as "VWAP Weekly", VWAPmonthly as "VWAP Monthly", VWAPyearly as "VWAP Yearly",Band1UP,Band1DN

x-2.jpg y.jpg