what is the ideal battery percentage before recharging my iphone 14 pro max

Don't let the battery go below 20% if possible.

Enable Optimized Battery Charging and connect the phone to the power adapter and leave it connected all night....every night.

It is impossible to overcharge the phone.

If you can don’t let it get below at least 15-25% and charge it to 85%

Charge your iPhone when you sleep, and preferably on a regular schedule.