I bought my computer used and it came with the full version of Office 2007. which I use a lot. If I upgrade to windows 10 Am I going to lose that? I know back in the day office used to be offered with the Windows OS w/out it being a free trial, it was the full version right off the bat, then they did away with that and only gave trial versions. For me it doesn't matter what version of Office I have as long as it's a full version and works , but I am doubting Windows 10 will come with a full version of office - couldn't get that lucky
If you do a normal upgrade you can keep your data and application in place. Should work fine I expect.
I can vouch that Office 2007 works fine on Windows 10. It will still be there after you upgrade, or if you do a clean install and have the Office install media and key, you will be fine.