VHDL Aggregate Error

Try the following code and see if it works for you.

library IEEE;
Use IEEE.Std_logic_1164.all;
Use IEEE.Std_logic_unsigned.all;
Use IEEE.Numeric_Std.all;
Use IEEE.Std_logic_arith.all;
 
Entity final_game_01 Is
  Port(
        enable : In std_logic;
        clk    : In std_logic; 
       --  score0, score1 : out std_logic_vector (6 downto 0);
        LED    : Out std_logic_vector (8 downto 0)
      );
End Entity;
 
Architecture RTL Of final_game_01 Is
 
Signal Count_M9 : std_logic_vector(3 downto 0);
Signal Count_M13: std_logic_vector(3 downto 0);
Begin
-- Mod-9 Counter
      Process (clk, enable) 
      Begin
        If(enable = '0') then
           Count_M9 <= "0000";
        Elsif (enable = '1') then
          If (clk = '1' and clk'event) then
             If (Count_M9 = "1001") then
                Count_M9 <= "0000";
             Else
                Count_M9 <= Count_M9 + '1';
             End If;
          End If;
        End If;
      End Process;
 
-- Mod-13 Counter
      Process (clk, enable) 
      Begin
        If(enable = '0') then
           Count_M13 <= "0000";
        Elsif (enable = '1') then
          If (clk = '1' and clk'event) then
             If (Count_M13 = "1101") then
                Count_M13 <= "0000";
             Else
                Count_M13 <= Count_M13 + '1';
             End If;
          End If;
        End If;
      End Process;
 
-- Compare counters and drive LEDs
 
  Process (Count_M9, Count_M13)
  Begin
    If (Count_M9 = "0000" and Count_M13 = "0000") then
       LED <= "000000001";
    ElsIf (Count_M9 = "0001" and Count_M13 = "0001") then
       LED <= "000000010";
    ElsIf (Count_M9 = "0010" and Count_M13 = "0010") then
       LED <= "000000100";
    ElsIf (Count_M9 = "0011" and Count_M13 = "0011") then
       LED <= "000001000";
    ElsIf (Count_M9 = "0100" and Count_M13 = "0100") then
       LED <= "000010000";
    ElsIf (Count_M9 = "0101" and Count_M13 = "0101") then
       LED <= "000100000";
    ElsIf (Count_M9 = "0110" and Count_M13 = "0110") then
       LED <= "001000000";
    ElsIf (Count_M9 = "0111" and Count_M13 = "0111") then
       LED <= "010000000";
    ElsIf (Count_M9 = "1000" and Count_M13 = "1000") then
       LED <= "100000000";
    Else
       LED <= "000000000";
    End If;
  End Process;
End RTL;

It's just two counters (Mod 9 and Mod13) running in parallel and the outputs of the counters drive the LEDs as you've mentioned.