i am a beginner to writing music and i am trying to start a band but i am unable to come up with any sort of lyrics or music and i do not have a clue about keys or music theory (only 13 only know tabs and other easy stuff! : )
First, don't bother quoting your age. You're a beginner in the field; people over the age of fifty would be experiencing the same thing if they had only just started.

Secondly; if you're worried about music theory, go take some lessons or something. If you can't afford it, hey, you're on the net, and there's a maelstrom of resources out there for you. Not only music theory and guitar, but also about lyrics, inspiration, music making etc. coming here was a good start, it allows you to swap verbals with other guys in similar situations.

Start with some covers in your band, get real right together and soon you can start bringing in your own stuff as you all get more experienced.

Writing-wise; just start writing. We all suck for the first year at least but it soon pays off if you work hard and are willing to take critisicm and learn from it, whilst keeping your own way of writing.

Apart from that, read, listen to music, just keep an eye on everything in the world. It helps.
My lovely friend,

First I teach you how to read chors:
I'll write the strings down for you like EADGBE
you must read the chords in the smae order. And where the 'x' comes
you mustn't play that string. And the numbers are the positions on that
string of your guitar.

Ok now the next chords:

Em = 022000
G = 320003
D9 = xx2323
C9 = xx0101

Play this chords in the same order as above and end in Em.

Good luck.