It's "normal" for a 700 x 25mm tire to lose up to 5-10% psi in 24 hrs.
I have had tubes that have exceeded this and found that the Presta valve core needed to be "snugged down"...
Nothing is more important than proper tire inflation.
For best results, if possible, top up your tires before every ride.
As a "starting point" - for 25mm tires:
100 psi in the front.
110 in the back.
YRMV.