Hi Tammy, welcome!

There is alot of info here and I understand it can feel like a lot all at once - the nice thing is you can read and interact (ask questions, etc.) at your own pace.
I'm not familiar with VOT - there are wide and varied opinions on whether or not certifications are important. I've never pursued one and it's not affected my practice or my ability to contract clients over the long term negatively, but I know other VAs who have and are glad they did.
I think if the material they offer is worthwhile to you as a business owner, as a VA, etc. then it may well be worth the investment - but don't pursue it just for the certification - your potential clients are not likely to even notice or know what it is. A learning experience should be about increasing your skill set, your knowledge, your confidence more than anything else. If VOT offers something along those lines then go for it