Look at all your fluid reservoirs to see if any of them are low. Based on what you find, look for a leak in that system. For example, if the brake master cylinder is low, look for leaks in the brake hoses. If the power steering is low, look for leaks there.
Check the transmission fluid level, while idling in neutral while the engine and transmission are hot. If it is low, this may be the culprit.
Crawl underneath and see if you see any red or clear fluid dripping anywhere. Red will either be transmission fluid or power steering (as the same fluid is used in power steering), clear would be brake fluid. Orange-ish would be coolant. Golden or brown is engine oil.
The CV joint is a good thing. However, if the boot is broken that is a bad thing. That is unlikely, given you only have 30,000 miles, and what is in there is grease, not fluid.
It is possible what you are seeing is condensation from the air conditioning compressor. That leaks, in front of the passenger footwell, and is perfectly normal, even in the winter.
I can't think of any fluid that would leak around the underside of the car and splash onto your door. I would bet that is due to an unrelated, separate incident. Run it through a car wash for that one.
2005 Dodge Grand Caravan SXT, 129K mi.
Former owner of:
1988 Dodge Caravan SE, 2.5L I4 (1988-1995, 99K mi); 1995 Plymouth Grand Voyager SE "Rallye", 3.3L (1995-2004, 169K mi); 2003 Grand Caravan Sport, 3.8L, (2004-2008, 106K mi), 2008 Nissan Quest, (2008-2010, 25K mi)
2008 Lexus RX400h (Dark Gray), 112K mi; 2005 Hyundai Elantra GT (Blue), 89K mi