No one is ever "ready" to have kids. They don't even require a license. There is no age requirement. Parenting is a job you grow into with "on the job" training. And, like it or not, you learn by your mistakes and your parent's and their parent's.
On the other hand, if you think you're not ready, don't. And don't do it for any reason other than you want to have a child. Children can't fix a bad marriage, live the life you didn't, or replace a warm fuzzy puppy.