@rmadrid20 - you want some type of disconnect out by the pump so that when working on the pump electricity one can disconnect it out there and not have someone flip the circuit breaker back on. The QO200TR will work or as @Gene said simple pull out disconnect. As HD lists the QO200TR for ~$17 and a pull out disconnect for ~$8, I’m not sure I’d take the time to swap them out.
Per the terrific diagram that Gene posted, the black wires coming from the circuit breaker panel will go into one side of the disconnect box. I couldn’t find a picture of the actual connections, so I’m flying blind, but look for terminals labeled Line 1 and Line 2. On the other side of the disconnect switch, Load 1 and Load 2, connect those to the L1 in and L2 in (I think they are black) wires for the pump start relay. The L1 out and L2 out (I think they are red) wires go to the actual pump. It shouldn’t matter which wire goes to L1 or L2 or the pump terminals as they both carry current.
Finally, the MV/P and C(ommon) wires from the Rachio ports are connected to the blue 24 VAC wires in the pump start relay. It doesn’t matter which wire goes to which on the 24 VAC circuit.