My 2 centavos on battery life:
Some actually do experience less battery life initially after making wholesale changes.
My money says battery life will improve on the next full charge & reboot.
One other major item of note:
You're new to Android & no doubt have peeked around in the app store.
My guess is you've seen apps promising better performance & battery life,Cleaning your phone to make it better/etc......
STAY AWAY FROM THESE APPS:
They're Snake Oil at minimum & usually worse: Data Mining apps/Snoopware.
Just take a look at the permissions of the apps you want download.
If the permissions seem to be overreaching for their intended purpose,don't install it,it's Crapware/Snoopware/data mining.................