So I'm new to Inkscape and I'm making a logo in a vector format and I have the entire logo finished. The logo has two O's in it and the insides of the O's are white. They look fine in the program, but when I export them, the insides of the O's are solid white where everything else is transparent. I need the insides of the O's to be transparent as well because I need to send the file off to a company to have T-shirts made. This seems like it would be a simple fix, but I can't seem to figure it out. Can anyone help me?

By your description it seems that the inner parts are drawn by white objects.

Somehow you have to subtract them from the "O"'s.
The design scenario you wrote can be made in several ways, and the fixing of the problem can be done in different ways for them.

Please provide a more precise explanation of the design you have, post some images, or
preferably attach the svg here, so that we can help you out.

The situation with "O"s can be tricky. There are a few different ways that the O might be drawn, and it depends how it's drawn, as to how to make the center tranparent. It could be Difference (subtract) as Lazur URH suggested. Or it could be changing the fill rule, or it could be combining paths, or it could be reversing one of the paths.

It sounds like the O might not be text?

Yes, the SVG file will help us figure out what to do

If you are saving or exporting the file that may be what is causing that to happen. EPS automatically fills in ANY transparency with a solid white background, no way around it in an EPS. I would check with the printer and see what other extensions/formats (jpg, png, gif, etc) do they accept, and use one that will retain transparency.
A work around method is to make the space in the O's the same color as the product (i.e. if the tee shirt is black, make the space black).
It gets difficult when things go to a printer... Please let us know more info, even if you don't want to include the file here - like how you are saving it, are you exporting it, are you exporting then opening in GIMP, etc, etc.

I imagine the font itself is the problem. Too bad the original post lacks information. I would have found the font name and its source helpful for solving the problem.

If capital Os have a white fill in Inkscape, this can be fixed by breaking the letters apart, highlighting the complete O and using a tool like Path > Difference.

I don't have any broken fonts to test this on though.