Car troubles!!

[MrGood]

Well two days ago i decided to wash my '04 F150 then after i got done i was gonna drive it up and down the road to finish drying it off.. Well i get in and turn the key.. click click click click........ damnit!.. my uncle jumps it and i let it run for a little while.. Later that day i go and put a different battery in it.. About 10 minutes ago i start it up and let it sit, and when it idles it like sounds as if its gonna shut off and then revs back up a little and back and forth and i drove it around a couple blocks to see if warming it up would make a difference as im turning back onto my road, the power steering goes out.. So i put it in park, shut it off, and start it back up and its fine but its still idling the same as before.. I have no knowledge about anything when it comes to vehicles so yah.. Any ideas?