Can’t delete + apps invisible

I now have an iPhone XR that was previously owned by my mother and since I have factory reseted and put my iCloud data from my iPhone 6S+, there is always at least on malfunctioning. Every time I restarted my phone to fix a bug, another one would start. It has stopped changing bugs but this time there is 2 and I cannot fix it with what I tried. The first one; my phone storage is full. It’s not a bug, but let me explain. Every time I try to delete something from my phone -Photos, videos, files, apps, etc.- it will reinstall it immediately. This is apparently because I have no more free storage, but how would I free storage if I cannot remove anything from my phone? The second problem I have on my phone, is that apps on the home screen are not visible. The only thing that appears on screen are folders (visually empty), the cloud icons because the apps are uninstalled and apps that cannot be deleted. This bug is also because of

supposedly because I do not have enough free storage. So uh how do i fix this all?