Hello ringi1950,
We see you're having issues with font sizes on your iPhone, and we'd be happy to help.
Are you experiencing this in all apps, including the Home Screen? If you need to access Settings, you may ask Siri to open that up as well: Use Siri on all your Apple devices
It sounds like the Zoom feature may be on. This page helps to go over that: If your Home screen icons are magnified on your iPhone, iPad, or iPod touch
As this page will note, "If you can't access Settings because your Home screen icons are magnified, double tap with three fingers on the display to zoom out."
Once in Settings, you can find available settings for Zoom and text sizes in Settings > Accessibility.
Cheers.