Welcome to the forum!
Let me put on my psychic hat....
Hhmm, unfortunately it seems to be on the fritz.
Based on the limited info, I would guess that something might be in a group, or possibly a clone....or possibly you have imported a raster image?? Oorrr....if it really is an SVG font, I guess they might already be paths, so that object to path would not be necessary. I'm not sure, I guess I've never really worked with an SVG font.
You can use the status bar to find out what kind of object is selected. Whenever the Selection tool is enabled, the status bar tells you what kind of object is selected. If it says "Group of...." then all you need to do is Ungroup. Object menu > Ungroup, or there's a button
or there's a key shortcut (Help menu > Key and Mouse Reference). If it says "Image...." you're on the wrong path (meaning "trail").
When you say you're having trouble putting something with all the fonts, I guess you're talking about the new font you purchased? Inkscape requires that fonts be installed on the operating system, before it can use them. If you don't know how, you'll have to find out how to install the font. If it's Windows, just double-click on the font file, and either it will be installed right away, or you'll see an "Install" button.
However, if the font is not installed, that makes me wonder what you're doing on the canvas with Object to Path and Union. Because if the font was not installed you wouldn't be able to type the letters. Ooorrr....maybe SVG fonts are different, and don't need to be installed??? I just don't know much about SVG fonts.
Please provide the SVG file with whatever you have in it. And also please tell us specifically what you're trying to do - I mean which objects for which actions.
