Last week my Acura TSX 2006 failed to start. When I turned the key, the dashboard lights would flicker and the ignition wouldn't start at all.

Figured it was a dead battery, So I bought a new battery and threw it in. Started up great immediately for the next few days but when I went to start it up recently. It struggled a bit. I thought "Hmm that's strange, it's a brand new battery..." but ignored it since it still started

It continued to struggle to start a bit and do this for the next couple of days and I kept thinking maybe it was parasitic drain or something. So I did some Googling and found out about the Bluetooth Hands-Free Receiver that can drain the battery and all you have to do is pull the passenger side panel off and unplug the module connector. I thought "oh damn this must be the issue, i'll go out and do this now"

Anyways I unplugged the Bluetooth Module from the side panel and went to start the car up again and it struggled to start up even more this time and just barely started. I road it around for 20minutes and came back. Turned it off. Let it sit and then attempted to turn it back on again. This time it was no-go and the dashboards flickered and there was no ignition again like last time. I panic'd and thought maybe it was the Bluetooth Module that I unplugged. So I plugged it back in and then tried to start it again and this time it started up again! But it struggled a bit like before....

Then I attempted to start it a few more times just to see and it seemed to start better/faster the second and third time and only struggled during the first attempt.

So I went riding for a bit more, came back home. Turned it off. Started it again and once again the whole thing repeated. It just BARELY was able to crank the engine to start the first time but seemed to start easier the second and third time I attempted it

So what the hells going on here? Why is my car struggling to start on it's first attempt (even when the car has been ridden right before) but then starts smoothly on the second or sometimes even third attempt?

I'm guessing it's the starter maybe? I don't have a ton of experience with cars so I'm not entirely sure what signs to be looking out for.