2006 Cadillac SRX won't start

wont start new batter next day dead where is the fuse box

Open your owners manual - that book in the storage box - and look up “fuses” in the back of the book. It will tell you what page tells you where the fuse boxes are on this car.

But your problem is not a fuse.

@Mustangman is right. Your problem is not a fuse.

You have something drawing power and draining the battery overnight.
The big culprits are the lights in the glove box, in the trunk, under the hood (if equipped) and that you left the dome light on. Other than the dome light, the others are controlled by switches that tell that you opened the glove box etc… Check with a fully charged battery and the ignition off, by opening the glove box etc., and feeling the bulb. If the bulb is warm…there is your problem.