I agree with the other posters who suggest learning the SOPs is important; but that doesn't mean a home simulator can't be useful as an "interactive" tool while learning the systems and procedures.
On X-Plane, there is a free 737-800 known as "Zibo" which is pretty good.
On MSFS and Prepar3D there's the PMDG version but I'm not sure whether they have an -800.
I personally prefer X-Plane as a flight simulator and hence would go with the Zibo but this can be down to preference.
In any case the free 738 by Zibo is more than enough for your intended purpose.