I'm writing a story for a series

Its exactly as it sounds, my friend has been obsessed with this so called dream project of his he wants to create a long running animation series. The problem however is we don't know how to do shit, we gotta learn everything from scratch sketching, lining, colouring, storyboarding, animating, sound design, video editing and a whole lotta stuff which doesn't bother me at all. I have took it upon myself to give the story of our series a direction (which has proven to be a bumpy ride). So far we don't have even 1 concept for our story that we would like to expand upon except pointers upon pointers of how we want our story to be, I'm in desperate need for help here. Can you pros give advice on how is a story actually started when you don't have any foundation to work on. P.S - my friend and I have made a document to track our progress in which I've mentioned mostly story pointers for myself. If anyone is interested I will edit this post and attach the doc to it later :)