Ok,had to replace electric cooking stove and when I plugged in the new one the electric kicked off.. I unplugged it and flipped the main breaker back on.. wondering why it did that?

Hi breeze and welcome, are you saying that just plugging in a new stove caused your main breaker to trip?

Yes.I don't know what Im doing,all I know is,the range I have is over 15+yrs old,has a 4 prong plug in.Anywho,bought another stove and it had a three prongs on it.I asked a friend of mine if he would help me out with this(yes,Im a female.. lol)and he switched the cords.He doesn't know much eigther:)We plugged it in and the electric went off.. I went back and flipped the big switch that says main on it,and electric came back on.Stove is unplugged.Should he put the 3 prong plug in back on the stove.I don't know.. At the moment too broke to hire an electrician and really like this newer stove.

I appreciate your help.

Youy need a 4 wire cord, and needs to be wired by someone Competent/Qualified. They will separate the Strap where the cord connects, so the Neutral and Ground are separate and Isolated from each other.
The cord didn't cause the short, The miswiring is likely.
If this is not Remodeling or new construction, The 3 wire cord could be installed on new dryer.(Ground to Neutral Strap needs to be reconnected)

Humm,very interesting.He hooked the red wire to the first terminal,there's a white wire and black wire on the secound,and the last is black.. no ground strap.. stove was a three prong,so we thought we would just put the 4 prong on and all would be dandy.. nope.. kicked off the main breaker.. I just don't know,yes right now I would love to have a qualified electrition come to the house,but don't have the funds at the moment.. so I have to figure this out by asking and looking up everything I can find and comprehend.. I truelly appreciate your help,I do.am grateful.

Take a photo of the wiring connections and post here.

The White is the Center Terminal, Red and Black are the outer 2 terminals. The Black on the center terminal is what's causing the short.
Do all work unplugged, Tighten connections good, as loose connections generate heat.