Expound featured post layout

I’m using Expound for my website – and it is a fantastic theme! – but would like to control which posts show up where. I have five main categories, and would like one post from each category to be featured on the homepage in a set order – and to stay in that set order instead of most recent featured post moving to the top and everything else shifting down one. I’ve read other members talking about child themes and CSS – I’m not familiar with either of these, as I am very new to this. Any ideas?