Planning for a second baby?

So this might be a weird question but I'd like to know how you planned for your second baby? I had my son in 2017, I was 18 and it was an unplanned pregnancy from an abusive relationship. I was a single mom for the first year and a half till I met my current partner. We have talked a lot about wanting more kids and would love to start preparing ourselves. Since I never got to prepare or plan for my first I want to be able to do all that stuff for my second and actually be ready and able to experience everything from the very beginning (as it was a long time before I tested and found out and accepted my first pregnancy). What products did you have to get for your second and what can you reuse from your first? How did you prepare financially? How did you know you were ready to start trying? How did you know you were prepared enough? Any advice would be greatly appreciated, especially if you have had a first unplanned pregnancy and then planned for your second.