I should have mentioned that I upgraded with "softaculous."
For those who don't know, softaculous is a web application found in cpanel, and is often provided by web hosting companies.
I should have also taken better notes.
As I remember, the upgrade also required a php module called "intl". I had to contact my web hosting company to provide that. I think it also required a another php module (I cannot think of the name), but my web hosting company provided that as well.
It was also suggested that I change MySQL to the barracuda file format, but I did not do that. I am not certain if I can - I will have to talk to my web hosting company.
Since I did not have any important content in my 3.3 installation, I did not take any precautions, or follow any instructions.
For the most part, my installation went quickly, and smoothly. But I did lose my h5p plugin, and all of my h5p content. I just thought I would let others know before they upgraded.