can I charge my phone overnight it's a 14 plus

Yes.

I used to do that before the new optimized battery charging feature was added and had no issues but this new feature is even better. See: About Optimized Battery Charging on your iPhone - Apple Support

Yes, you can do that without any problems. Most people charge their mobile at night. However, make sure there is air around it, and do not put it under a pillow or similar, and remember to use an original charger.

When you wake up again, you can find more information about Optimized Battery Charging:

About Optimized Battery Charging on your iPhone - Apple Support