Late to the party, but if you know how to diagnose and fix technical problems via google, you should be fine with MySQL. It's pretty easy to set up and use. This forum is actually powered by MySQL.

I'd recommend hosting it on AWS or Azure, especially if you depend on it for your business. That way, somebody else is on the hook to provide all the uptime and resiliency, and it's someone with enough resources to guarantee they do a good job on it. I've been running a SQL server on Azure for the past five months, and that's been very easy and painless. I'm paying only about $20 a month, and I hit that database pretty hard (~10 queries a second of varying complexity, 24/7). I have no direct experience with Azure MySQL, but I imagine it's basically the same and just as easy to set up and run.