I have found a lot of luck watching YouTube videos of specific things that I am trying to accomplish. I am a visual learner so it helps for me to see someone do it. Other than that Tableau does have some solid resources too. But there certainly isn’t as much support for learning possible Tableau functionalities when comparing to a more traditional software like Excel.
I also agree with John. I bought a Tableau class from Udemy for $10, and the material was presented in a very helpful, clear way. Sometimes the courses can be more expensive, but they have sales several times throughout the year, so it might make sense to wait to buy until one is happening. I bought a class on Tableau almost two years ago, and I still have access to it, so it doesn’t seem like they ever expire. Very useful if you ever want to go back for a refresher.
During the start of the semester, I faced a similar situation where Tableau was introduced in the course ISyE 412 and I was completely new to it. So, once I installed the software I got a free learning tutorial, a good introduction to tableau from https://elearning.tableau.com/, which helped me getting used to the interface. As the Course progressed, I explored a lot of features by working more on the software regularly and the course project helped as understand the true power of data visualization.