Hi there @awakeninghearts,
Thanks for reaching out, I’ll help you here 🙂
First of all please review our Themer’s guide to get a sense of how to tweak our plugin style and templates. Specifically for font and size changes, you can also check the article Basic font and color changes with CSS.
Regarding your update question, yeah you just need to click on the ‘Update Now’ button for each plugin and that should be all. It’s always recommended to update first in a staging site to see if the update works as expected first, and after confirming it then update in the production site. I strongly recommend to do so in your case as you are updating from an ‘pretty old’ version to the latest.
Please let me know about how this goes,
Best,
Nico