To add to what Jeff said, DBA in the cloud is a VERY similar skill set to DBA on premise. On the back end, it is all the same thing - it is SQL Server. The differences more come into play when you administer the host of the SQL instance.
The "Brent Ozar" of SQL on the cloud is the "Brent Ozar" of SQL on premise. If you are using Azure, are you running SQL inside a VM on the cloud OR is it a managed instance OR is it an Azure SQL instance or is it a SQL Edge instance OR are you running it outside of Azure? If you are running SQL inside a VM (on or off Azure), then the process of administration of the SQL stuff is pretty much 100% identical to on-premise. The administration of the VM is a bit different, but even that is very similar. And even then, an expert in Azure MAY offer bad advice if you were hosting in AWS (for example).
My opinion - your best bet is to talk to people and learn from everyone. Post specific questions you have here and learn from the SSC experts. SQL has a TON of stuff, I would be willing to bet that Brent Ozar even has a "Brent Ozar" he goes to for help on certain things. I am 100% confident that NOBODY knows everything about a specific host for SQL be it in the cloud or on site. And even when you think you know everything, Microsoft introduces a new feature or changes how things work in the back end and then the experts need to learn the new stuff. For example, if you asked how you can do a running total in SQL Server, there are multiple ways to do it. If you are on a newer SQL version, you can use LAG and sum things up. If you are on an older version, you may need to do some fancy stuff with a tally table. Or if you really want to make your query slow, you could use a cursor.
The above is all just my opinion on what you should do.
As with all advice you find on a random internet forum - you shouldn't blindly follow it. Always test on a test server to see if there is negative side effects before making changes to live!
I recommend you NEVER run "random code" you found online on any system you care about UNLESS you understand and can verify the code OR you don't care if the code trashes your system.