What i would do is just do an oil/tranny fluid change, change to one of the highmileage oils suggested above in the thread. Also check the level of all the other fluids and top up as necessary. Fill up the tank to full, reset your odometer trip a/b and drive it...see how your gas mileage is and from there on you can decide if you should do a tuneup on it or not.
As for cleaning the interior...the best way would be a steamer for the cloth, and a soft brush and vacuum cleaner for dash/trim pieces.
The quick way would be a scrubber, a soft brush for the dash, some soap foam and a vacuum cleaner.