Not starting

I have the car listed above that as of Saturday would not crank. The battery terminals were not the best so we changed those and even then, it still would not crank. We noticed that it would crank after trying. So, we thought okay, the starter must have a flat spot, so we got a new one and put it on. It still will not crank and is now making a different noise than it did to begin with! The crank shaft makes like five tapping noises and then the starter is making like a machine gun sound. I am starting to think that maybe it isn’t getting enough power.
Sorry if I’m talking in circles but making sure I covered everything so bear with me. I have been without a car for 4 days, missed work and almost missed my father-in-law's funeral so it’s been an emotional few days
Basically, breaking down everything looks normal. But when you put the key in it turns on everything is functioning, it’s just not starting though. It makes a cranking sound that sounds like it’s coming from some piece in the back corner but other than that nothing more or less. We tested the battery and alternator, and they are good. The starter got replaced because it had a flat spot in it because we did the method of turning the key until it came in which worked every time, but now that we have replaced the starter that method no longer is useful. We checked relays wires everything. We are sure electrical just dk what else to do because we already searched Google and YouTube and did just about everything since Saturday.