Preparing for TTC???

I think I want to start trying for baby number 2 in a couple months. I want to know what I should do in advance to prep my body. I didn’t really do anything to prepare for my first baby and I had some pregnancy complications. I want to be better for my second baby. I’ve started working out more and I’m the lowest weight I’ve been in probably 5 years, but according to BMI I need to lose more. Is this super important? I’m 170 and 5’5” what else can I do to prep besides just losing weight?