What should I be focusing on?
My app: https://play.google.com/store/apps/details?id=com.betalystfootballbettingtips&hl=en_GB
These days it's more the standard quality stuff. Start with good naming criteria and description text. Then get lots of downloads, good reviews, continuous users etc. App quality will strongly reflect in your position.
Overall you've entered a very competitive area. Unless this app offers a distinct benefit so people clamor to it organically you're going to have to buy your exposure.
Do you know the expected financial value of a download? If not work this out. Then decide how much margin you need to make and then get spending if the numbers stack up. These days tricking you way to the top aint going to work in this category.