Simple Font Size and Color Editing

I’ve been given the joyful task of making small changes to our website. A company created our website and passed me the info to login to wordpress and change our site. So I found the page I needed to change some text color and add a link to. So I highlighted the text (in visual mode) changed the color to one line and added a link to another, hit save and to my surprise (not) the newly colored text is smaller. I see no option to change the text size. I’ve spent a few hours reading through some of the other posts on here and started uploading plug-ins, activating them, no luck. I saw a “3-step” instruction (there were 4 btw, I guess “step 0” doesn’t count) for installing the latest wordpress (each step had at least 3 sub-steps). It was confusing as heck and I’m afraid I’ll disable our website if I mess with that.

So, my question is: for someone like myself who doesn’t know a thing about this “program” that wants to simply change font sizes and color, what is the easiest and/or quickest option?

Thank you.