WTF PLEASE HELP MY CAR IS INSANE!

ok i have no idea what is wrong with my car. fri evening after work i go out to start it nothing happens. i think maybe battery? so i get a jump nothing. then it starts clicking like it could be? so anyway then it does absolutely nothing. no sounds no cranking. it's pouring rain and i try anything i can think of. finally just called a tow truck an hour later they come and i put it in nuetral and then i crank it . it starts? and put back in drive runs fine. ran fine all the way home 25+ miles. so the next day i try to start it and starts right up. i don't drive it. anyway so today i tried to start it today and nothing. i tried all the same things nothing. then i hear a weird sound. i notice when i open my door my elec fan comes on and when i shut it it turns off. this is w/o the key on or even in. what could it possibly be and where do i start?
please help me!!!!!!!

i checked all the wiring and cables they are all clean and are making good connection. the battery has juice. no draining. how exactly or why would the fan come on just from opening the door w/o a the key in or anything? no starting at all.

ttt

yes i checked all the fan wiring it looked perfect nothing outta place. the battery still had power for all the lights and such. it still would not crank.