What are the consequences of attempt of theft & why am i being charged?

(Keep note that i don't know word by word nor what exactly i said since it was back in january)
One day i skipped school & went to my girl who's a friends house (she's not my friend anymore) she & her friend found or stole (don't remember) a purse with a phone in it & makeup ect ect girl stuff. They told me to sell it (i didn't not have nobody in mind since i doubt anybody wants a cracked iphone 4) but i said alright.

The next day my other friend told me the situation about her friend being robbed by a girl which was my old friend, friend.
I took out the phone & asked if it was her friends, she said if she could hold it to make sure, turns out it was.
Not sure if it was the next day or later on that day but a detective called me down to the schools officers office to questioned me.
Ofcourse i lied since i was scared but ended up telling the truth. Not sure if i said it was stolen or not but the detective said to write my report & i could leave
(There was the schools officer & one of the principles there as witnesses)
I was recently formed that i was charged with attempt of theft & missed my court date since the court never sent the citation.
How am i being charged with attempt of theft when i returned the phone before the detective questioned me & the girl who got robbed pressed charges on just the girl.
Should i fight this case or plea guilty & what are the consequences if i do plea guilty?

Well first of all you're straight up stupid you need to wear a helmet to that court date and from the description of your friends it sounds like you have a miserable existence and should be killed off from the population