dirt bikes???????????????????????????????????????????

That would depend upon which crf150 you have. The crf150f is a basic trail bike suitable for a beginner rider and someone your age. The crf150r is the racing version which is much more powerful and would probably be a bit much for someone who has never ridden.

Make sure you do purchase all the basic safety gear before you ride including boots. You should be able to set yourself up with less expensive brand stuff for around $500 to $700 possibly cheaper as I am used to only purchasing the more expensive stuff as it gets a lot of use.