What all do you need before you get pregnant?

So my fiancé and I have baby fever, and have for a while. I’m 20, he is 23. We have been recently talking about maybe starting TTC in the near future. We are both done with college.

We are new home-owners (3 bed 2 bath.. so we have an extra room we can use as a nursery)

we both have pretty decent jobs. We make over the average household income in our state. My job offers 16 weeks paid maternity leave. We have insurance, cars, etc.

What else do you need before you start TTC? Financially? How much savings should you have, etc. if that makes sense.

How do you prepare properly for a baby physically and mentally as well? I know it’s obviously too soon to prepare everything as I’m not even pregnant yet, but when we eventually do start trying and get pregnant, we want it to be as stress free as possible, and not having to worry about money or anything.

Also health wise, what should we do to decrease our risks of baby having any birth defects? How can we increase the chances of a healthy pregnancy?

Thanks!!