I actually taught myself Tableau a number of years ago. There is a free public version of it where you can create an account. You have to download the latest version of the application, locally, then you can upload your data vizzes to your Public profile. They’re always updating the software too, so you’ll always have the most current version. They have some cool, new functionality where you can now even edit your data visualization online, rather than opening up the app on your machine and editing an already published viz.
Tableau has a YouTube channel and so many ‘how to’ videos about every aspect of the application:
They also have a HUGE community where you can find help when you need it. I’ve watched almost all their videos (they update them when they update the software too) and have attended some live trainings as well. All free. (i mean, you have to register for them though). Oh, and they have a “Makeover Monday” that’s on YT where a Tableau “Zen Master” redoes data vizzes live and then others participate and do their own revisions. It’s pretty neat.
Don’t let the specifics in job posts deter you from applying. Most times employers are looking for a unicorn candidate. If you show your willingness to learn new technologies and have a portfolio of your work as well as linking your GitHub on your cover letter and LinkedIn profile, that helps too.