You can’t directly change the size of just the time and notifications on the top left, but there are some ways to make them look bigger:
1. Settings > Display > Display size and text (or Screen zoom) – Slide it to larger, and it’ll make the icons + text in the status bar a bit bigger.
2. Settings > Accessibility > Visibility enhancements – Turn on larger font or bold text, which can help make the time more readable.
3. If you have the Good Lock app (from Galaxy Store), install QuickStar. It lets you tweak some status bar settings (depends on your One UI version though).
Hope that helps! If you're on a newer One UI version, more options might be coming too.