Few "minor" problems

[Wizard50369]

So I figured out what my hard starting was. The sensor at the bottom of the thermostat housing was unplugged. Plugged it in and Wee it started. Now I have a coolant leak somewhere. Big. After running the car for a few minutes and taking off the radiator cap, the coolant does this surge kinda thing. Sucks in than spits it back out. If i let my car sit for X amount of time and come back to it, theres no coolant in it.
White smoke (not a big cloud though) coming from tail pipe, water in the oil, lack of power (not too much loss) all made me believe it was the head gasket. The problems are getting worse.

Second, when I went to start it up today, there is no spark at any of the spark plugs.

Im off to work which is why im not researching this right now, but any help would be good. Like where do i start looking at for the no spark? And is it the head gasket leading to the other problems? Thanx for any help