What to do before Trying!!! help!

Philadelphia
I'm 24 and I've been with my SO for 7 years we love eachother dearly but he wants to wait another two or three years to have kids. (We aren't married) He says he wants to be in a better place at work and financially. I bought a condo and took in my sisters kids a few years back and they are now with partners and thinking about school both graduated so I'm looking at space freeing up at home. I've already had one miscarriage and it broke our hearts but I really want to have kids and I'm worried the more time goes by the harder it will be. I struggle with fibromyalgia and I work a lot. What should my goals be before we start trying and is there anything I should try to accomplish before I get pregnant? Please help Ladies!!! I need a parents advice is there anything you wish you did differently before you got pregnant?