As a Founder, a big part of your job is keeping the lights on by ensuring there is money in the bank and you have a healthy runway (or are already profitable).
Links to great resources on startup funding and finances:
https://medium.com/swlh/diligence-at-social-capital-part-1-accounting-for-user-growth-4a8a449fddfc
https://foundersnetwork.com/blog/startup-financials/