If you have limited time and want to be familiar with terms, try a site Investopedia. Here, you get to understand concepts and terms, e.g. WACC https://www.investopedia.com/terms/w/wacc.asp
Or quickmba.com. Or mbaskool.com. mbaskool has one bit called 'business concepts' or smtg. This should prove useful.
If you have time to spare and are targetting something specific (e.g. financial accounting vs. cost/management accounting, then sites like https://www.principlesofaccounting.com/ would be useful.
There's also MOOC. Join Coursera, etc. There should be courses that are specific to your needs.
Hope this helps.