Bubble is an incredible tool, but it takes an incredible amount of time to get comfortable with. It has one of the biggest toolsets and comparably the most functionality all in one place, but it's going to take a few weeks of consistent practice at least before you're able to really nail it.
Bubble is incredibly functional once you know how to use it, and you can build nearly anything you can imagine with this platform, completely custom. You'll be able to publish to the web with a custom domain, there are larger paid plans with increased backend server capacity if needed, and best of all, a massive set of educational videos to teach you how to get comfortable with the platform, to compensate for the learning curve.
While it is incredibly functional, there are some drawbacks to Bubble besides its high learning curve. You cannot natively publish a mobile app to the app store on Bubble, only web apps (although you can still use web apps on mobile devices), and while there are some services to transfer your Bubble apps to a mobile app format, I've heard the transition isn't always perfect. Bubble will also not let you publish any apps/sites you've built to the web unless you're on a paid plan, so this is very much a paid-only product. You can still build and experiment and test on the free plan, though!
Almost everything you'll need is on Bubble's lowest paid plan of $29 per month - which you'll need to publish anything anyway. Larger plans are available, but they're primarily for if you need a lot more data storage or server capacity.