Try this
declare @FDt date
declare @TDt date
Set @Fdt = DATEADD(year,-1,GETDATE())--set parameter from date
set @TDt = GETDATE() --set parameter to date
SELECT T0.CardCode, T0.CardName, T1.SlpName, T1.Commission, Min(O1.DocDate)'First SO'
,isnull((Select SUM(LineTotal) FROM RDR1
WHERE DocDate between @Fdt AND @TDt and SlpCode= T1.SlpCode and BaseCard= T0.CardCode),0) Yr_Total
FROM OCRD AS T0 INNER JOIN
OSLP AS T1 ON T0.SlpCode = T1.SlpCode INNER JOIN
RDR1 O1 ON T1.SlpCode = O1.SlpCode
WHERE (T0.CardType = 'C')
group by T0.CardCode, T0.CardName, T1.SlpName, T1.Commission, T1.SlpCode