Plugins not working Tinymce.

Hello,
I am trying to access help in this are. I changed my site a month ago to https://Lorislittlelessons.com. I was posting and adding H1 tags and the visual administrator ( I think that’s the name was fine it had the basic things such as font size H1 tags. Now it is not working properly and just has the basic. I tried to download and research a way to get the buttons to work, but n success downloading Tiny Mce. I am not a pro at this, but a novice trying to get my website across to help people. I really appreciate some feedback.
I am not sure how to install ..
Thanks,
Lori