Improving site reliability for beginners?

Hey everyone, I'm a super new SaaS founder here, just launched my very first app and honestly, I'm trying to wear all the hats right now, which is proving to be quite the challenge. One of the biggest areas I'm struggling with is handling all the 'Website Maintenance & cPanel Management Services' myself. It's truly overwhelming, and as I start to see a tiny bit of traffic trickle in, my biggest concern is definitely maintaining site reliability. I'm dreading the thought of my site going down just as users start discovering it. So far, my efforts have been pretty basic – I log into cPanel for manual backups every now and then, and I try to keep plugins updated when I remember. But it's all very ad-hoc, and I don't really have a structured approach to website support beyond these reactive steps. I'm feeling a bit lost on what I should really be focusing on. What are the absolute core, non-negotiable tasks for a solo founder like me to ensure consistent site reliability for a SaaS product? Also, at what point should someone in my position seriously consider professional 'Website Maintenance & cPanel Management Services' instead of trying to DIY everything? Is there a traffic threshold or a complexity level where it just becomes unsustainable for a single person? And lastly, are there any common beginner mistakes in cPanel management or general website upkeep that severely impact site reliability? I'm sure I'm probably making a few without even realizing it. Any advice or insights from you experienced folks would be incredibly helpful and genuinely appreciated. Help a brother out please...