ok so what letter encounter should i start off with? im also kind of confused on how to read the map. should i just read the book straight through?
The map should be on the cover. It shows a canyon with a number of caves and passages. The PCs will enter from the right-hand side.
You may wish to read the text on page 14 to your players, which begins "The forest you have been passing through has been getting more dense, tangled, and gloomier than before." and ends "You know that you have certainly discovered the Caves Of Chaos.".
After that, I'd say something like this:
Two caves are fairly close to you. One stands on the southern side of the bluff to your left. A little way ahead and to your right, you can see a cave overhung by a large, twisted tree.
That describes cave D (to the left) and cave A (to the right).
Running this, I will have read all of the early cave descriptions, especially cave A (1-6) and cave D (17-21) and cave E (22).
If the players choose to go left (D):
Inside the cave mouth, you see a 10 foot wide passageway running twenty feet before reaching a crossroads; the passages seem to have been carved out of the rock.
If the players choose to go right (A):
Roll a d6; if you roll a 1 or 2:
As you approach the cave and begin to peer inside, suddenly it's raining small, dog-headed humanoids from the tree above! Kobolds! They run forward brandishing long daggers and attack!
Proceed to your first combat.
Alternatively, if you roll a 3-6:
Inside the cave, the passageway runs twenty feet before reaching a T-junction. A small dog-headed humanoid - a kobold - peers nervously around the corner from the right-hand side before disappearing with a bark of dismay, and you can hear it running away calling an alarm!
Note that there's a guardpost of 6 kobolds just inside the cave-mouth at 1. The kobolds will not step on the pit-trap, although your players might as they chase the kobolds...
Cheers!