Do they stay near the mouth of the creek closest to the main lake or swim further up. I ask because the creek i fish is about a mile from the main lake but stays 8-10 ft. Would i need to jon boat down closer to the lake?

All of the above.

You should be in good shape with 8-10 ft. water.

half way! if they swim any further they would be swimming out of the creek

They'll go as shallow as a foot or two when the water is murky.

Crappie, just go to shallow areas or they jusy go to feeder creek? But since there is no rain to wash anything down, will bait fishes and crappies just stay stay near of in main lake?

I bet right now you can catch crappie very shallow on the main lake in coves and flats since the warm spell will draw the shad there and the water will be ~58 or warmer.

However when it gets colder you need at least enough "creek" to create an area warmer and more sheltered than the general lake. The slough by my house (Lake Lewisville) for instance has been pretty much empty of crappie during past winters and it is rather creek like but not a true feeder creek. I hear of lakes that hold shallow crappie year round though. Will be interested to read other opinions.