Tough question 🙂

Taking classes in SQL Server really only teaches you the fundamentals of administration and design. And yes, you could jump straight from these classes into a job.

That said, if you are joining a company as the only DBA, you'll have a steep learning curve ahead of you. If the previous DBA left the environment in a healthy state, then it buys you some time to get to grips and learn (a lot) more about SQL Server. On the other hand, if the previous DBA left the environment with performance problems, bad database designs etc then you really are trying to run before you can walk and I would not advise this for a new DBA.

If I was in your position, however, I would be more interested in looking for junior roles. This site is a fantastic medium for learning and you also cannot beat having experienced DBA's sitting across the room from you.

Good luck