Newly self employed and have no idea where to start 🫣

Can anybody point me in the right direction of what it is I need to do to be able to get Mat pay? I started my business in Feb this year, and due to have my baby in December. Being so new I’m absolutely clueless to the whole self employed world and don’t even know where to start🫣 I’ve read about it all having to do with NI and I can make contributions?