How to declare variables in T-SQL from select statements

Question

declare @Week nvarchar(16) = quotename(concat('Week',@CID,@SID));
declare @Week2 nvarchar(256) = concat('SELECT TOP 1 [Year],[Week] FROM',@Week,'GROUP BY [Year],[Week] ORDER BY [Year] DESC,[Week] DESC');

exec sp_executesql @Week2

how can I declare @Year and @Week respectively from the result of exec sp_executesql @Week2? (declare as in assign the result values into @year and @week)

Thanks

declare @latestyear NVARCHAR(50), @latestweek NVARCHAR(50)
declare @Week2 nvarchar(256) = 'SELECT TOP 1 @latestyear=[Year],@latestweekweek=[Week] FROM [Week45] GROUP BY [Year],[Week] ORDER BY [Year] DESC,[Week] DESC';
exec sp_executesql @Week2
PRINT @latestyear
PRINT @latestweek

The above doesn't seem to work for me

Also trying to do this in 1 select statement if possible