Need Major Advice!

My fiancé and I have been together for 7 years before getting engaged (got engaged July of this year) and getting married December of 2020.I am 22 turning 23 in a month and he’s 23. We always wanted to be younger parents and been talking about whether or not to start trying while we can now so that I can have the baby a few months before our wedding so that I can have time to lose weight and get my body back and also have the baby in early summer so that i can get a teaching job by next school year. We also have concerns of getting my career started (I graduate in December of this year) I want to be a teacher and he’s pretty much in his career field but wants to be a firefighter (he’s currently an EMT). Also we want to buy a house.We really need others experience stories and advice of what to do whether if it’s trying right now or waiting until another 2-3 years. Please help me!