I began my self-education as a graphics designer (and animator) on Visio. It is extraordinarily easy to use, once you familiarize yourself with the options, what things can do, how to arrange and adjust and manipulate shapes. It was quite easy to learn and some of the clunky features of the earlier Visio versions I was learning on have been improved with time. It's modernized with a ribbon bar and I find it easier to navigate and locate what I'm looking for. It doesn't overwhelm you with so many options with strange names that could intimidate new users, like Photoshop and programs like that can do. Although I'm not a fan of them, there are templates, which I understand can sometimes be balky when trying to use. I always preferred a new blank to work with. (I don't use templates in any of the software programs I have that offer them. It's just my weird thing.) If you can use it for free through your school or work, that's a bonus, because it is on the expensive side, which I'll address under the Cons of Visio.
As I said above, the price is definitely a factor to consider. And I think the templates aren't always as user friendly as they should be, if you're the kind who uses templates. A lot of the things that I now know, as an experienced graphics designer and animator, were clunky and difficult and needed improvement, actually have been improved over the years, so the clunky, hard to maneuver issues from earlier versions is for the most part gone. There are still areas for improvement and a little imagination, but Visio is a solid, reliable, easy to use program, especially if you can use it for free.