Based on what you have shared, it sounds like QuickBooks Online will work for you. However, I do recommend that you have the errors fixed before you convert to QuickBooks Online. You should hire a QuickBooks ProAdvisor to come in and fix the issues with your desktop file. For tips on how to find & locate a good ProAdvisor in your area, check out this article:
We also have an article on the steps you need to take to convert from desktop to online. You can find it here:https://fitsmallbusiness.com/convert-quickbooks-desktop-to-online/.
All the Best-