Small amounts of water are normal, you will get some water inside the hull from washing the boat, it will leak in in small amounts through rhe anchor locker, some salt spray on really rough days might find its way in there too, but were talking little amounts that over time might show as a small puddle. The biggest accumulation will come from the deck, the caulk needs to be checked, if it is peeling or coming up replace it. Also, the in deck circular hatch covers need new gaskets every other season, and if opened a bit for sea cock access, every season. If you have sea cocks and the boat is left in the water, close them when possible, that way they cannot leak over time and if a hose breaks or a clamp loosens or breaks you do not sink the boat. I recommend checking all the in deck screws as well, over time they tend to loosen on some, but not all Grady's. On both Grady's we've owned, I took one day where it was really windy and removed them all and resealed them with a proper sealant so they remained water tight, and also so any water on deck does not seep in and years down the road cause the deck to go soft. Very simple task that is well worth the effort, will also keep some water from seeping into the bilge.
If you ever do have a build up of water that is abnormal, check your sea cocks first, also make sure the bilge pumps work. From time to time I will actually put a gal or 2 of water in to let them run if no water is present, and when I come on plane after a big rain storm I will plow and give the boat a big trim angle and let the water build aft then flip the pump on to get rid of anything I can, also lets you know the pumps are working since my boat rarely ever accumulates enough to gon on at the dock or while at rest.
Best of luck and enjoy the boat!!!