In washington to be an actually ''doula'' yes you need to have a little cert training. It is only a 3 month course.
I to after having kids came to the realization i hated retail. which is my full back ground of working. I have been out for so long no one wanted to hire me as a manager. I went back as a parttimer to my last job, it was horrible having the shoe on the other foot so to speak.
I woke up one morning, and it just hit me, I will do the doula training so i can make some money to bring to the table, go back to school to become a full blown midwife. I told myself since i have had my tubes tied i cant ''have another'' I sure as hell though wanted to be apart of the magic of women giving birth. I think your heart is in the right place for it. I would look into classes at your local community college or like the one I am going to be taking is thorugh a technical college.
good luck on your journey I hope you do get to become a doula... We need more out there.