Unable to run self-developed app on my phone

I built an app on my computer using xcode and I want to try running it on my iphone. Whenever I press run it shows me an error saying "Please delete apps signed with your free account from this device to remain under the limit." I don't know what it means. I checked other threads to see if there was a solution and I tried some things where I disconnected devices with my apple id, I unpaired my phone and then paired it again, etc. If anyone has any solution for my problem, I would seriously appreciate it.