You can start with Opening the Samsung Members app Click on Support & Diagnostics then run the Diagnostics for the Battery to check it's health.
You could also check to see that your apps are being Optimized & limit the background usage of apps that you don't really use.
If it's been a year, backing up your device with Smart Switch & Factory Reset can also improve the battery life during the day.
There's more that you can do, but this should get you started.
Before you factory reset you should check by going to Settings, Battery and Device care, Battery and see which apps are using the most of your battery. You can touch different parts of the graph and see which apps are using the most at different parts of the day