Not starting or turning over

So I bought this car 2 weeks ago and now its not wanting to start. It is a 2000 Honda Civic LX standard. I changed the starter and alternator but in order to get it running, I have to push start it. The battery isn’t staying charged at all anymore and when I try to turn it on there is no click or trying to turn over or anything. When I got the battery checked, it checked out fine. The fuel pump, catalytic converter, timing belt, and battery just got changed 2 years ago so I don't think it could be one of those things. Does anyone have any recommendations for what could be wrong with it?

It is still not clear why you started changing parts before diagnosing them bad.

If you battery tested bad start here. Try to jump start the car and if/when it starts verify that the alternator produces enough voltage (>13 volts). You may take the alternator to Autozone (if you have them in in Texas) to bench test it.

I believe that even with the weak battery your fuel pump should run. Open the filler neck and have somebody listen it the pump hums when you turn the ignition to start.

Good luck,
Sam

Good luck,
Sam