Seperation

I have my first legal aid appointment with the actual solicitor that is taking on my case. I am seeing them for help after my seperation from my childrens father (1yrold and baby on the way) in regards to support and custody. What sort of documents should I be accumulating?
I have our parenting plan and correspondence where he refuses to assist with prenatal costs (apparently there is a whole part of the law that states is liable for costs), refusing to financially assist and see our son and how the entire messy situation went down (financial abuse and abandonment). But thats it. I'm not really sure what else is needed and the correspondence is through text so I'm not sure how reliable it would be in this instance.