Noticed last night that hardly any air is coming out of vents, so when I checked unit, I noticed water on the floor. Felt the line and had Frost at top and bottom. Then took out air filter and stuck hand inside and felt a drip.

Any suggestions on where to start?

I have spent much of the last week fighting the similar problems on some A/C units at my church. Made it through an important, packed 3 hour service Thursday night OK. Check the air filter and drain. If the filter gets dirty enough, I think the blower can drop the pressure low enough water can't flow out of the unit. When it shuts off, the water that built up inside gushes out faster than the drain can handle. With a clean filter and drain, the condensate should go wherever the drain does. With the air flow restricted, you don't have enough warm air flowing to keep the coil above freezing. There could be other problems, perhaps requiring a technician to remedy, but first make sure the air is flowing like it should. May need to check the blower too.

Checked the air filter and not too dirty. Walked outside to look at the fan unit and the pipe coming from the unit that goes into the ground is covered with frost all the way solid. Already put a call into a technician, but could that frost on the outside be a determining factor of what it most likely is?

What you need to check is the fan or blower in your furnace. When installed, it should have been sized or adjusted to give enough air flow to prevent freezing.

Okay. Just opened up the side of the inside unit and basically everything around coils and all is solid with frost. I'm just going to wait for technician to come out. Thanks for the help though. Guess it's problems like these that get us to understand the units better for next time.

If this just started then I would suspect Low Refrigerant, Dirty Evaporator Coils or depending on your system and expansion valve malfunction . At the outside unit or Condensing unit you should have a Big line which should be insulated and a small line ;the Big line should sweat( be cool or cold) not form ice and the small line should be Hot to the touch if these are not the case then you would have problems as stated.