I appreciate your interest in knowing more about QuickBooks Online (QBO), shanen.
It will be my pleasure to help you learn more about how things works in QBO. With that, may I know what specific help you need to learn about invoicing, categorizing and reconciling?
For now, let me share these articles that provides all you need to know about the topics mentioned above:
I'll also leave you with the following resources that includes video tutorials, articles and webinars so you'll become more familiar with QBO's features and function:
Thanks for choosing QuickBooks. If you have other questions, just leave me a reply below and I'll be sure to get back to you. Wishing you an your business continued success.