Where are you? What type of dogwood are we talking about? This can make a significant difference, especially in whether the full-sun exposure is ideal.

ONE wilted leaf and A spot or TWO! Unless it's a plastic tree, this doesn't sound unusual at all (even for an established tree).

As for whether there are any problems, you haven't given us anything to base an answer on, so far at least.

im in south east tennessee and the dogwood is cornus florida and by one wilted leaf i mean its been kinda weatherd down

Cornus florida planted in full-sun in east Tennessee is the norm and will not be a problem at all.

thanks a bunch what if the temps are 90+? should I water weekly

The best way to determine how often you should water is to check for moisture levels around AND in the rootball. Take a look at section 12 in the link below. Here in my area (Knoxville), once a week probably isn't quite enough in very hot weather, but you shouldn't really use someone else's watering situation to judge your own because conditions might vary.

BTW, I hope you chose one of the more disease resistant cultivars.

Here is a link that might be useful: see Section 12

thanks for the link and im about 200 miles from you (ooltewah)
and im sad to say but one dogwood died thanks to tyty nursery by disease but were looking at some well known cultivatars and have placed an order about 10 minutes ago. thankyou so much again :P