My iPhone is showing only apple logo what can i do ?

See this support document, If your iPhone is stuck on the Apple logo - Apple Support

Have you damaged your iPhone in any way, shape or form? If so, the damage taken by the iPhone might be contributing to it. If not, it might be due to a hardware fault that naturally occurred or a software-related issue.

I'm not an expert, I haven't owned an iPhone since the iPhone 4 but have used an iPad 5 from 2017-2019.

That's actually a useful document. I shall refer to it should my future XR have that issue.